Advanced Strategies for Stabilizing Single-Atom Catalysts for Energy Storage and Conversion

Jansi Rani, B., Ravi, G., Yuvakkumar, R., et al.: CoNiSe2 nanostructures for clean energy production. ACS Omega 5, 14702–14710 (2020). https://doi.org/10.1021/acsomega.0c01476 Olivos-Suarez, A.I., Szécsényi, À., Hensen, E.J.M., et al.: Strategies for the direct catalytic valorization of methane using heterogeneous catalysis: challenges and opportunities. ACS Catal. 6, 2965–2981 (2016). https://doi.org/10.1021/acscatal.6b00428 Hosseini, S.E., Abdul Wahid, M.: The role of renewable and sustainable energy in the energy mix of Malaysia: a review. Int. J. Energy Res. 38, 1769–1792 (2014). https://doi.org/10.1002/er.3190 Dincer, I., Acar, C.: A review on clean energy solutions for better sustainability. Int. J. Energy Res. 39, 585–606 (2015). https://doi.org/10.1002/er.3329 Sørensen, B.: A sustainable energy future: construction of demand and renewable energy supply scenarios. Int. J. Energy Res. 32, 436–470 (2008). https://doi.org/10.1002/er.1375 Duan, J., Tang, X., Dai, H.F., et al.: Building safe lithium-ion batteries for electric vehicles: a review. Electrochem. Energy Rev. 3, 1–42 (2020). https://doi.org/10.1007/s41918-019-00060-4 Wu, D., Peng, C., Yin, C., et al.: Review of system integration and control of proton exchange membrane fuel cells. Electrochem. Energy Rev. 3, 466–505 (2020). https://doi.org/10.1007/s41918-020-00068-1 Lokhande, P.E., Chavan, U.S., Pandey, A.: Materials and fabrication methods for electrochemical supercapacitors: overview. Electrochem. Energy Rev. 3, 155–186 (2020). https://doi.org/10.1007/s41918-019-00057-z Lu, J.J., Yin, S.B., Shen, P.K.: Carbon-encapsulated electrocatalysts for the hydrogen evolution reaction. Electrochem. Energy Rev. 2, 105–127 (2019). https://doi.org/10.1007/s41918-018-0025-9 Jia, Y.F., Yuan, Y., Sun, J., et al.: Porous PEDOT network coated on MoS2 nanobelts toward improving capacitive performance. ACS Sustain. Chem. Eng. 8, 12696–12705 (2020). https://doi.org/10.1021/acssuschemeng.0c04791 Friedl, J., Lebedeva, M.A., Porfyrakis, K., et al.: All-fullerene-based cells for nonaqueous redox flow batteries. J. Am. Chem. Soc. 140, 401–405 (2018). https://doi.org/10.1021/jacs.7b11041 Braun, P.V., Cook, J.B.: Deterministic design of chemistry and mesostructure in Li-ion battery electrodes. ACS Nano 12, 3060–3064 (2018). https://doi.org/10.1021/acsnano.8b01885 Zhou, G.M., Xu, L., Hu, G.W., et al.: Nanowires for electrochemical energy storage. Chem. Rev. 119, 11042–11109 (2019). https://doi.org/10.1021/acs.chemrev.9b00326 Wang, Y.J., Yang, Y., Zou, L.L., et al.: Carbon-supported W@Pt nanoparticles with a Pt-enriched surface as a robust electrocatalyst for oxygen reduction reactions. ChemistrySelect 3, 1056–1061 (2018). https://doi.org/10.1002/slct.201702493 Li, Y.W., Zhang, W.J., Li, J., et al.: Fe-MOF-derived efficient ORR/OER bifunctional electrocatalyst for rechargeable zinc–air batteries. ACS Appl. Mater. Interfaces 12, 44710–44719 (2020). https://doi.org/10.1021/acsami.0c11945 Vinod Selvaganesh, S., Selvarani, G., Sridhar, P., et al.: Graphitic carbon as durable cathode-catalyst support for PEFCs. Fuel Cells 11, 372–384 (2011). https://doi.org/10.1002/fuce.201000151 Chen, C., Kang, Y.J., Huo, Z.Y., et al.: Highly crystalline multimetallic nanoframes with three-dimensional electrocatalytic surfaces. Science 343, 1339–1343 (2014). https://doi.org/10.1126/science.1249061 Mohanta, P.K., Regnet, F., Jörissen, L.: Impact of highly stable catalyst support materials on polymer electrolyte membrane fuel cell performance. Energy Technol. 8, 2000081 (2020). https://doi.org/10.1002/ente.202000081 Sun, R.L., Xia, Z.X., Qi, F.L., et al.: Efficient design for a high-energy and high-power capability hybrid electric power device with enhanced electrochemical interfaces. ACS Appl. Mater. Interfaces 11, 19943–19949 (2019). https://doi.org/10.1021/acsami.9b01863 Yao, Y., Wang, J., Shahid, U.B., et al.: Electrochemical synthesis of ammonia from nitrogen under mild conditions: current status and challenges. Electrochem. Energy Rev. 3, 239–270 (2020). https://doi.org/10.1007/s41918-019-00061-3 Wang, X.Q., Li, Z.J., Qu, Y.T., et al.: Review of metal catalysts for oxygen reduction reaction: from nanoscale engineering to atomic design. Chem 5, 1486–1511 (2019). https://doi.org/10.1016/j.chempr.2019.03.002 Wang, Y., Wang, D.S., Li, Y.D.: A fundamental comprehension and recent progress in advanced Pt-based ORR nanocatalysts. SmartMat 2, 56–75 (2021). https://doi.org/10.1002/smm2.1023 Keith, J.A., Jacob, T.: Theoretical studies of potential-dependent and competing mechanisms of the electrocatalytic oxygen reduction reaction on Pt(111). Angew. Chem. Int. Ed. 49, 9521–9525 (2010). https://doi.org/10.1002/anie.201004794 Zhang, B.W., Wang, Y.X., Chou, S.L., et al.: Fabrication of superior single-atom catalysts toward diverse electrochemical reactions. Small Methods 3, 1800497 (2019). https://doi.org/10.1002/smtd.201800497 Zhu, C.Z., Fu, S.F., Shi, Q.R., et al.: Single-atom electrocatalysts. Angew. Chem. Int. Ed. 56, 13944–13960 (2017). https://doi.org/10.1002/anie.201703864 Wang, Y.X., Su, H.Y., He, Y.H., et al.: Advanced electrocatalysts with single-metal-atom active sites. Chem. Rev. 120, 12217–12314 (2020). https://doi.org/10.1021/acs.chemrev.0c00594 Hlatky, G.G.: Heterogeneous single-site catalysts for olefin polymerization. Chem. Rev. 100, 1347–1376 (2000). https://doi.org/10.1021/cr9902401 Ye, R., Zhao, J., Wickemeyer, B.B., et al.: Foundations and strategies of the construction of hybrid catalysts for optimized performances. Nat. Catal. 1, 318–325 (2018). https://doi.org/10.1038/s41929-018-0052-2 Wang, M., Chen, L., Sun, L.C.: Recent progress in electrochemical hydrogen production with earth-abundant metal complexes as catalysts. Energy Environ. Sci. 5, 6763–6778 (2012). https://doi.org/10.1039/c2ee03309g He, Q., Lee, J.H., Liu, D.B., et al.: Accelerating CO2 electroreduction to CO over Pd single-atom catalyst. Adv. Funct. Mater. 30, 2000407 (2020). https://doi.org/10.1002/adfm.202000407 Jiao, J., Lin, R., Liu, S., et al.: Copper atom-pair catalyst anchored on alloy nanowires for selective and efficient electrochemical reduction of CO2. Nat. Chem. 11, 222–228 (2019). https://doi.org/10.1038/s41557-018-0201-x Sun, L.B., Reddu, V., Fisher, A.C., et al.: Electrocatalytic reduction of carbon dioxide: opportunities with heterogeneous molecular catalysts. Energy Environ. Sci. 13, 374–403 (2020). https://doi.org/10.1039/c9ee03660a Wang, X., Peng, X., Chen, W., et al.: Insight into dynamic and steady-state active sites for nitrogen activation to ammonia by cobalt-based catalyst. Nat. Commun. 11, 653 (2020). https://doi.org/10.1038/s41467-020-14287-z Yang, Y.L., Li, F., Chen, J., et al.: Single Au atoms anchored on amino-group-enriched graphitic carbon nitride for photocatalytic CO2 reduction. Chemsuschem 13, 1979–1985 (2020). https://doi.org/10.1002/cssc.202000375 Zhong, L.X., Zhang, L.M., Li, S.Z.: Understanding the activity of carbon-based single-atom electrocatalysts from ab initio simulations. ACS Mater. Lett. 3, 110–120 (2021). https://doi.org/10.1021/acsmaterialslett.0c00419 Singh, B., Sharma, V., Gaikwad, R.P., et al.: Single-atom catalysts: a sustainable pathway for the advanced catalytic applications. Small 17, 2006473 (2021). https://doi.org/10.1002/smll.202006473 Xie, C., Yan, D.F., Li, H., et al.: Defect chemistry in heterogeneous catalysis: recognition, understanding, and utilization. ACS Catal. 10, 11082–11098 (2020). https://doi.org/10.1021/acscatal.0c03034 Zhang, B.L., Yu, H.Y., Wang, J.Q., et al.: Synthesis of CeO2 nanoparticles with different morphologies and their properties as peroxidase mimic. J. Am. Ceram. Soc. 102, 2218–2227 (2019). https://doi.org/10.1111/jace.16071 Jin, R.C., Li, G., Sharma, S., et al.: Toward active-site tailoring in heterogeneous catalysis by atomically precise metal nanoclusters with crystallographic structures. Chem. Rev. 121, 567–648 (2021). https://doi.org/10.1021/acs.chemrev.0c00495 Ma, Z., Dai, S.: Development of novel supported gold catalysts: a materials perspective. Nano Res. 4, 3–32 (2011). https://doi.org/10.1007/s12274-010-0025-5 Zuliani, A., Ivars, F., Luque, R.: Advances in nanocatalyst design for biofuel production. ChemCatChem 10, 1968–1981 (2018). https://doi.org/10.1002/cctc.201701712 Srinivasan, S., Demirocak, D.E., Kaushik, A., et al.: Reversible hydrogen storage using nanocomposites. Appl. Sci. 10, 4618 (2020). https://doi.org/10.3390/app10134618 Gadipelly, C., Mannepalli, L.K.: Nano-metal oxides for organic transformations. Curr. Opin. Green Sustain. Chem. 15, 20–26 (2019). https://doi.org/10.1016/j.cogsc.2018.08.002 Vignarooban, K., Lin, J., Arvay, A., et al.: Nano-electrocatalyst materials for low temperature fuel cells: a review. Chin. J. Catal. 36, 458–472 (2015). https://doi.org/10.1016/S1872-2067(14)60175-3 Thoda, O., Xanthopoulou, G., Vekinis, G., et al.: Review of recent studies on solution combustion synthesis of nanostructured catalysts. Adv. Eng. Mater. 20, 1800047 (2018). https://doi.org/10.1002/adem.201800047 Niemann, M.U., Srinivasan, S.S., Phani, A.R., et al.: Nanomaterials for hydrogen storage applications: a review. J. Nanomater. 2008, 950967 (2008). https://doi.org/10.1155/2008/950967 Mohamed, R.M., McKinney, D.L., Sigmund, W.M.: Enhanced nanocatalysts. Mater. Sci. Eng. R Rep. 73, 1–13 (2012). https://doi.org/10.1016/j.mser.2011.09.001 Jung, N., Chung, D.Y., Ryu, J., et al.: Pt-based nanoarchitecture and catalyst design for fuel cell applications. Nano Today 9, 433–456 (2014). https://doi.org/10.1016/j.nantod.2014.06.006 Ambat, I., Srivastava, V., Sillanpää, M.: Recent advancement in biodiesel production methodologies using various feedstock: a review. Renew. Sustain. Energy Rev. 90, 356–369 (2018). https://doi.org/10.1016/j.rser.2018.03.069 Fukuzumi, S., Yamada, Y., Suenobu, T., et al.: Catalytic mechanisms of hydrogen evolution with homogeneous and heterogeneous catalysts. Energy Environ. Sci. 4, 2754–2766 (2011). https://doi.org/10.1039/c1ee01551f Shen, H., Li, Y.J., Shi, Z.Q.: A novel graphdiyne-based catalyst for effective hydrogenation reaction. ACS Appl. Mater. Interfaces 11, 2563–2570 (2019). https://doi.org/10.1021/acsami.8b00566 Liang, H., Li, T.R., Zhang, J., et al.: 3-D hierarchical Ag/ZnO@CF for synergistically removing phenol and Cr(VI): heterogeneous vs. homogeneous photocatalysis. J. Colloid Interface Sci. 558, 85–94 (2020). https://doi.org/10.1016/j.jcis.2019.09.105 Zhou, J., Zhang, Y., Li, S., et al.: Ni/NiO nanocomposites with rich oxygen vacancies as high-performance catalysts for nitrophenol hydrogenation. Catalysts 9, 944 (2019). https://doi.org/10.3390/catal9110944 de Vos, A., Lejaeghere, K., Muniz Miranda, F., et al.: Electronic properties of heterogenized Ru(II) polypyridyl photoredox complexes on covalent triazine frameworks. J. Mater. Chem. A 7, 8433–8442 (2019). https://doi.org/10.1039/c9ta00573k Ge, R.Y., Huo, J.J., Liao, T., et al.: Hierarchical molybdenum phosphide coupled with carbon as a whole pH-range electrocatalyst for hydrogen evolution reaction. Appl. Catal. B Environ. 260, 118196 (2020). https://doi.org/10.1016/j.apcatb.2019.118196 Ge, R.Y., Li, W.X., Huo, J.J., et al.: Metal-ion bridged high conductive RGO-M-MoS2 (M = Fe3+, Co2+, Ni2+, Cu2+ and Zn2+) composite electrocatalysts for photo-assisted hydrogen evolution. Appl. Catal. B Environ. 246, 129–139 (2019). https://doi.org/10.1016/j.apcatb.2019.01.047 Zhu, M.Y., Yu, S.J., Ge, R.Y., et al.: Cobalt oxide supported on phosphorus-doped g-C3N4 as an efficient electrocatalyst for oxygen evolution reaction. ACS Appl. Energy Mater. 2, 4718–4729 (2019). https://doi.org/10.1021/acsaem.9b00273 Huo, J.J., Chen, Y.L., Liu, Y., et al.: Bifunctional iron nickel phosphide nanocatalysts supported on porous carbon for highly efficient overall water splitting. Sustain. Mater. Technol. 22, e00117 (2019). https://doi.org/10.1016/j.susmat.2019.e00117 Li, W.X., He, X.F., Ge, R.Y., et al.: Cobalt porphyrin (CoTCPP) advanced visible light response of g-C3N4 nanosheets. Sustain. Mater. Technol. 22, e00114 (2019). https://doi.org/10.1016/j.susmat.2019.e00114 Ge, R.Y., Huo, J.J., Sun, M.J., et al.: Surface and interface engineering: molybdenum carbide-based nanomaterials for electrochemical energy conversion. Small 17, 1903380 (2021). https://doi.org/10.1002/smll.201903380 Desalegn, B.Z., Jadhav, H.S., Seo, J.G.: Highly efficient g-C3N4 nanorods with dual active sites as an electrocatalyst for the oxygen evolution reaction. ChemCatChem 11, 2870–2878 (2019). https://doi.org/10.1002/cctc.201900330 Liu, M.M., Wang, L.L., Zhao, K.N., et al.: Atomically dispersed metal catalysts for the oxygen reduction reaction: synthesis, characterization, reaction mechanisms and electrochemical energy applications. Energy Environ. Sci. 12, 2890–2923 (2019). https://doi.org/10.1039/c9ee01722d Liu, Q., Zhang, Z.L.: Platinum single-atom catalysts: a comparative review towards effective characterization. Catal. Sci. Technol. 9, 4821–4834 (2019). https://doi.org/10.1039/c9cy01028a Vancsó, P., Popov, Z.I., Pető, J., et al.: Transition metal chalcogenide single layers as an active platform for single-atom catalysis. ACS Energy Lett. 4, 1947–1953 (2019). https://doi.org/10.1021/acsenergylett.9b01097 Qiao, B., Wang, A., Yang, X., et al.: Single-atom catalysis of CO oxidation using Pt1/FeOx. Nat. Chem. 3, 634–641 (2011). https://doi.org/10.1038/nchem.1095 Lin, J., Wang, A.Q., Qiao, B.T., et al.: Remarkable performance of Ir1/FeOx single-atom catalyst in water gas shift reaction. J. Am. Chem. Soc. 135, 15314–15317 (2013). https://doi.org/10.1021/ja408574m Wang, Y., Arandiyan, H., Scott, J., et al.: Single atom and nanoclustered Pt catalysts for selective CO2 reduction. ACS Appl. Energy Mater. 1, 6781–6789 (2018). https://doi.org/10.1021/acsaem.8b00817 Sun, M.H., Ji, J.P., Hu, M.Y., et al.: Overwhelming the performance of single atoms with atomic clusters for platinum-catalyzed hydrogen evolution. ACS Catal. 9, 8213–8223 (2019). https://doi.org/10.1021/acscatal.9b02305 Zhang, X., Zhang, Z.H., Wu, D.H., et al.: K1–xMo3P2O14 as support for single-atom catalysts. J. Phys. Chem. C 121, 22895–22900 (2017). https://doi.org/10.1021/acs.jpcc.7b07643 Sun, J.F., Xu, Q.Q., Qi, J.L., et al.: Isolated single atoms anchored on N-doped carbon materials as a highly efficient catalyst for electrochemical and organic reactions. ACS Sustain. Chem. Eng. 8, 14630–14656 (2020). https://doi.org/10.1021/acssuschemeng.0c04324 Kunwar, D., Zhou, S.L., DeLaRiva, A., et al.: Stabilizing high metal loadings of thermally stable platinum single atoms on an industrial catalyst support. ACS Catal. 9, 3978–3990 (2019). https://doi.org/10.1021/acscatal.8b04885 Han, C.W., Iddir, H., Uzun, A., et al.: Migration of single iridium atoms and tri-iridium clusters on MgO surfaces: aberration-corrected STEM imaging and ab initio calculations. J. Phys. Chem. Lett. 6, 4675–4679 (2015). https://doi.org/10.1021/acs.jpclett.5b01884 Kwon, K.C., Suh, J.M., Varma, R.S., et al.: Electrocatalytic water splitting and CO2 reduction: sustainable solutions via single-atom catalysts supported on 2D materials. Small Methods 3, 1800492 (2019). https://doi.org/10.1002/smtd.201800492 Büchele, S., Chen, Z.P., Mitchell, S., et al.: Tailoring nitrogen-doped carbons as hosts for single-atom catalysts. ChemCatChem 11, 2812–2820 (2019). https://doi.org/10.1002/cctc.201900547 Sharifi, T., Gracia-Espino, E., Chen, A.R., et al.: Oxygen reduction reactions on single- or few-atom discrete active sites for heterogeneous catalysis. Adv. Energy Mater. 10, 1902084 (2020). https://doi.org/10.1002/aenm.201902084 Wang, A., Li, J., Zhang, T.: Heterogeneous single-atom catalysis. Nat. Rev. Chem. 2, 65–81 (2018). https://doi.org/10.1038/s41570-018-0010-1 Li, Z., Ji, S.F., Liu, Y.W., et al.: Well-defined materials for heterogeneous catalysis: from nanoparticles to isolated single-atom sites. Chem. Rev. 120, 623–682 (2020). https://doi.org/10.1021/acs.chemrev.9b00311 Wang, L.Q., Huang, L., Liang, F., et al.: Preparation, characterization and catalytic performance of single-atom catalysts. Chin. J. Catal. 38, 1528–1539 (2017). https://doi.org/10.1016/S1872-2067(17)62770-0 Lang, R., Li, T.B., Matsumura, D., et al.: Hydroformylation of olefins by a rhodium single-atom catalyst with activity comparable to RhCl(PPh3)3. Angew. Chem. Int. Ed. 55, 16054–16058 (2016). https://doi.org/10.1002/anie.201607885 Li, J.C., Wei, Z.D., Liu, D., et al.: Dispersive single-atom metals anchored on functionalized nanocarbons for electrochemical reactions. In: Shao, M.H. (ed.) Electrocatalysis. Topics in Current Chemistry Collections, pp. 127–148. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-43294-2_5 Wang, Q., Astruc, D.: State of the art and prospects in metal–organic framework (MOF)-based and MOF-derived nanocatalysis. Chem. Rev. 120, 1438–1511 (2020). https://doi.org/10.1021/acs.chemrev.9b00223 Song, Z.X., Zhang, L., Doyle-Davis, K., et al.: Recent advances in MOF-derived single atom catalysts for electrochemical applications. Adv. Energy Mater. 10, 2001561 (2020). https://doi.org/10.1002/aenm.202001561 Wang, H.F., Chen, L.Y., Pang, H., et al.: MOF-derived electrocatalysts for oxygen reduction, oxygen evolution and hydrogen evolution reactions. Chem. Soc. Rev. 49, 1414–1448 (2020). https://doi.org/10.1039/c9cs00906j Lu, X.F., Xia, B.Y., Zang, S.Q., et al.: Metal–organic frameworks based electrocatalysts for the oxygen reduction reaction. Angew. Chem. Int. Ed. 59, 4634–4650 (2020). https://doi.org/10.1002/anie.201910309 Guo, J.J., Huo, J.J., Liu, Y., et al.: Nitrogen-doped porous carbon supported nonprecious metal single-atom electrocatalysts: from synthesis to application. Small Methods 3, 1900159 (2019). https://doi.org/10.1002/smtd.201900159 Xu, J.T., Ouyang, J.Y., Fan, Z.Q., et al.: Polymer-supported half-titanocene catalysts for the syndiospecific polymerization of styrene. J. Polym. Sci. A Polym. Chem. 38, 127–135 (2000). https://doi.org/10.1002/(SICI)1099-0518(20000101)38:1%3c127::AID-POLA17%3e3.0.CO;2-8 Chen, W.X., Pei, J.J., He, C.T., et al.: Rational design of single molybdenum atoms anchored on N-doped carbon for effective hydrogen evolution reaction. Angew. Chem. Int. Ed. 56, 16086–16090 (2017). https://doi.org/10.1002/anie.201710599 Wei, Y.S., Zhang, M., Zou, R.Q., et al.: Metal–organic framework-based catalysts with single metal sites. Chem. Rev. 120, 12089–12174 (2020). https://doi.org/10.1021/acs.chemrev.9b00757 Chen, Y., Ji, S., Zhao, S., et al.: Enhanced oxygen reduction with single-atomic-site iron catalysts for a zinc-air battery and hydrogen-air fuel cell. Nat. Commun. 9, 5422 (2018). https://doi.org/10.1038/s41467-018-07850-2 Wang, X., Chen, W.X., Zhang, L., et al.: Uncoordinated amine groups of metal–organic frameworks to anchor single Ru sites as chemoselective catalysts toward the hydrogenation of quinoline. J. Am. Chem. Soc. 139, 9419–9422 (2017). https://doi.org/10.1021/jacs.7b01686 Wang, J.P., Han, G.K., Wang, L.G., et al.: ZIF-8 with ferrocene encapsulated: a promising precursor to single-atom Fe embedded nitrogen-doped carbon as highly efficient catalyst for oxygen electroreduction. Small 14, 1704282 (2018). https://doi.org/10.1002/smll.201704282 Chen, Y.J., Ji, S.F., Wang, Y.G., et al.: Isolated single iron atoms anchored on N-doped porous carbon as an efficient electrocatalyst for the oxygen reduction reaction. Angew. Chem. Int. Ed. 56, 6937–6941 (2017). https://doi.org/10.1002/anie.201702473 Ji, S.F., Chen, Y.J., Fu, Q., et al.: Confined pyrolysis within metal–organic frameworks to form uniform Ru3 clusters for efficient oxidation of alcohols. J. Am. Chem. Soc. 139, 9795–9798 (2017). https://doi.org/10.1021/jacs.7b05018 He, Y.H., Hwang, S., Cullen, D.A., et al.: Highly active atomically dispersed CoN4 fuel cell cathode catalysts derived from surfactant-assisted MOFs: carbon–shell confinement strategy. Energy Environ. Sci. 12, 250–260 (2019). https://doi.org/10.1039/c8ee02694g Zhao, J., Wang, Y.N., Dong, W.W., et al.: A new surfactant-introduction strategy for separating the pure single-phase of metal–organic frameworks. Chem. Commun. Camb. Engl. 51, 9479–9482 (2015). https://doi.org/10.1039/c5cc02043c Pan, Y.C., Heryadi, D., Zhou, F., et al.: Tuning the crystal morphology and size of zeolitic imidazolate framework-8 in aqueous solution by surfactants. CrystEngComm 13, 6937–6940 (2011). https://doi.org/10.1039/c1ce05780d Ji, S.F., Chen, Y.J., Wang, X.L., et al.: Chemical synthesis of single atomic site catalysts. Chem. Rev. 120, 11900–11955 (2020). https://doi.org/10.1021/acs.chemrev.9b00818 Jeong, H., Shin, S., Lee, H.: Heterogeneous atomic catalysts overcoming the limitations of single-atom catalysts. ACS Nano 14, 14355–14374 (2020). https://doi.org/10.1021/acsnano.0c06610 Kaiser, S.K., Chen, Z.P., Faust Akl, D., et al.: Single-atom catalysts across the periodic table. Chem. Rev. 120, 11703–11809 (2020). https://doi.org/10.1021/acs.chemrev.0c00576 Lang, R., Du, X.R., Huang, Y.K., et al.: Single-atom catalysts based on the metal–oxide interaction. Chem. Rev. 120, 11986–12043 (2020). https://doi.org/10.1021/acs.chemrev.0c00797 Nguyen, T.N., Salehi, M., Le, Q.V., et al.: Fundamentals of electrochemical CO2 reduction on single-metal-atom catalysts. ACS Catal. 10, 10068–10095 (2020). https://doi.org/10.1021/acscatal.0c02643 Zhuo, H.Y., Zhang, X., Liang, J.X., et al.: Theoretical understandings of graphene-based metal single-atom catalysts: stability and catalytic performance. Chem. Rev. 120, 12315–12341 (2020). https://doi.org/10.1021/acs.chemrev.0c00818 Liao, Y.Z., Cheng, Z.H., Zuo, W.W., et al.: Nitrogen-rich conjugated microporous polymers: facile synthesis, efficient gas storage, and heterogeneous catalysis. ACS Appl. Mater. Interfaces 9, 38390–38400 (2017). https://doi.org/10.1021/acsami.7b09553 Li, C.: Single Co atom catalyst stabilized in C/N containing matrix. Chin. J. Catal. 37, 1443–1445 (2016). https://doi.org/10.1016/S1872-2067(16)62520-2 Wu, G.H., Huang, H., Rong, J.F., et al.: Recent advances in non-noble metal single atom catalysts. Acta Petrolei Sinica 34, 639–650 (2018) Zhang, H.B., Liu, G.G., Shi, L., et al.: Single-atom catalysts: emerging multifunctional materials in heterogeneous catalysis. Adv. Energy Mater. 8, 1701343 (2018). https://doi.org/10.1002/aenm.201701343 Zhang, R.G., Peng, M., Ling, L.X., et al.: PdIn intermetallic material with isolated single-atom Pd sites: a promising catalyst for direct formic acid fuel cell. Chem. Eng. Sci. 199, 64–78 (2019). https://doi.org/10.1016/j.ces.2019.01.018 Ling, C.Y., Li, Q., Du, A.J., et al.: Computation-aided design of single-atom catalysts for one-pot CO2 capture, activation, and conversion. ACS Appl. Mater. Interfaces 10, 36866–36872 (2018). https://doi.org/10.1021/acsami.8b10394 Zhang, J., Sun, P., Zhao, Z.L., et al.: Application of heterogeneous catalysts in olefin hydroformylation. Chin. Sci. Bull. 64, 3173–3187 (2019). https://doi.org/10.1360/N972019-00160 Zhong, W.H., Zhang, G.Z., Zhang, Y.C., et al.: Enhanced activity of C2N-supported single Co atom catalyst by single atom promoter. J. Phys. Chem. Lett. 10, 7009–7014 (2019). https://doi.org/10.1021/acs.jpclett.9b02906 Liu, C.G., Jiang, M.X., Su, Z.M.: Computational study on M1/POM single-atom catalysts (M = Cu, Zn, Ag, and Au; POM =[PW12O40]3–): metal-support interactions and catalytic cycle for alkene epoxidation. Inorg. Chem. 56, 10496–10504 (2017). https://doi.org/10.1021/acs.inorgchem.7b01480 Karmakar, S., Chowdhury, C., Datta, A.: Noble-metal-supported GeS monolayer as promising single-atom catalyst for CO oxidation. J. Phys. Chem. C 122, 14488–14498 (2018). https://doi.org/10.1021/acs.jpcc.8b02442 Liu, S.Q., Liu, Y.W., Gao, X.P., et al.: Two-dimensional transition metal porphyrin sheets as a promising single-atom-catalyst for dinitrogen electrochemical reduction to ammonia: a theoretical study. J. Phys. Chem. C 124, 1492–1499 (2020). https://doi.org/10.1021/acs.jpcc.9b10294 Ling, C.Y., Ouyang, Y.X., Li, Q., et al.: A general two-step strategy-based high-throughput screening of single atom catalysts for nitrogen fixation. Small Methods 3, 1800376 (2019). https://doi.org/10.1002/smtd.201800376 Liao, T., Kou, L.Z., Du, A.J., et al.: H2S sensing and splitting on atom-functionalized carbon nanotubes: a theoretical study. Adv. Theory Simul. 1, 1700033 (2018). https://doi.org/10.1002/adts.201700033 Liao, T., Sun, Z.Q., Kim, J.H., et al.: Theoretically designed metal-welded carbon nanotubes: extraordinary electronic properties and promoted catalytic performance. Nano Energy 32, 209–215 (2017). https://doi.org/10.1016/j.nanoen.2016.12.033 Chen, L.N., Hou, K.P., Liu, Y.S., et al.: Efficient hydrogen production from methanol using a single-site Pt1/CeO2 catalyst. J. Am. Chem. Soc. 141, 17995–17999 (2019). https://doi.org/10.1021/jacs.9b09431 Liu, K., Hou, G., Mao, J., et al.: Genesis of electron deficient Pt1(0) in PDMS-PEG aggregates. Nat. Commun. 10, 996 (2019). https://doi.org/10.1038/s41467-019-08804-y Song, H., Rioux, R.M., Hoefelmeyer, J.D., et al.: Hydrothermal growth of mesoporous SBA-15 silica in the presence of PVP-stabilized Pt nanoparticles: synthesis, characterization, and catalytic properties. J. Am. Chem. Soc. 128, 3027–3037 (2006). https://doi.org/10.1021/ja057383r Wu, C.Q., Li, D.D., Ding, S.Q., et al.: Monoatomic platinum-anchored metallic MoS2: correlation between surface dopant and hydrogen evolution. J. Phys. Chem. Lett. 10, 6081–6087 (2019). https://doi.org/10.1021/acs.jpclett.9b01892 Zhao, D., Chen, Z., Yang, W.J., et al.: MXene (Ti3C2) vacancy-confined single-atom catalyst for efficient functionalization of CO2. J. Am. Chem. Soc. 141, 4086–4093 (2019). https://doi.org/10.1021/jacs.8b13579 Zhang, Y.L., Li, X.K., Li, K., et al.: Novel Au catalysis strategy for the synthesis of Au@Pt core–shell nanoelectrocatalyst with self-controlled quasi-monolayer Pt skin. ACS Appl. Mater. Interfaces 9, 32688–32697 (2017). https://doi.org/10.1021/acsami.7b08210 Zhang, L., Doyle-Davis, K., Sun, X.L.: Pt-based electrocatalysts with high atom utilization efficiency: from nanostructures to single atoms. Energy Environ. Sci. 12, 492–517 (2019). https://doi.org/10.1039/c8ee02939c Tang, Y., Wang, Y.G., Li, J.: Theoretical investigations of Pt1@CeO2 single-atom catalyst for CO oxidation. J. Phys. Chem. C 121, 11281–11289 (2017). https://doi.org/10.1021/acs.jpcc.7b00313 Yang, S., Kim, J., Tak, Y.J., et al.: Single-atom catalyst of platinum supported on titanium nitride for selective electrochemical reactions. Angew. Chem. Int. Ed Engl. 55, 2058–2062 (2016). https://doi.org/10.1002/anie.201509241 Yan, D.X., Chen, J., Jia, H.P.: Temperature-induced structure reconstruction to prepare a thermally stable single-atom platinum catalyst. Angew. Chem. Int. Ed. 59, 13562–13567 (2020). https://doi.org/10.1002/anie.202004929 Woo, H., Lee, E.K., Yun, S.W., et al.: Platinum single atoms on carbon nanotubes as efficient catalyst for hydroalkoxylation. Bull. Korean Chem. Soc. 38, 1221–1225 (2017). https://doi.org/10.1002/bkcs.11252 Langer, R., Fako, E., Błoński, P., et al.: Anchoring of single-platinum-adatoms on cyanographene: experiment and theory. Appl. Mater. Today 18, 100462 (2020). https://doi.org/10.1016/j.apmt.2019.100462 Peng, Y.H., Geng, Z.G., Zhao, S.T., et al.: Pt single atoms embedded in the surface of Ni nanocrystals as highly active catalysts for selective hydrogenation of nitro compounds. Nano Lett. 18, 3785–3791 (2018). https://doi.org/10.1021/acs.nanolett.8b01059 Wang, D.L., Li, H.P., Du, N., et al.: Single platinum atoms immobilized on monolayer tungsten trioxide nanosheets as an efficient electrocatalyst for hydrogen evolution reaction. Adv. Funct. Mater. 31, 2009770 (2021). https://doi.org/10.1002/adfm.202009770 Harrath, K., Yu, X.H., Xiao, H., et al.: The key role of support surface hydrogenation in the CH4 to CH3OH selective oxidation by a ZrO2-supported single-atom catalyst. ACS Catal. 9, 8903–8909 (2019). https://doi.org/10.1021/acscatal.9b02093 Jongkind, L., Caumes, X., Hartendorp, A.P.T., et al.: Ligand template strategies for catalyst encapsulation. Acc. Chem. Res. 51, 2115–2128 (2018). https://doi.org/10.1021/acs.accounts.8b00345 Lou, Y., Zheng, Y.P., Li, X., et al.: Pocketlike active site of Rh1/MoS2 single-atom catalyst for selective crotonaldehyde hydrogenation. J. Am. Chem. Soc. 141, 19289–19295 (2019). https://doi.org/10.1021/jacs.9b06628 Han, B., Lang, R., Tang, H.L., et al.: Superior activity of Rh1/ZnO single-atom catalyst for CO oxidation. Chin. J. Catal. 40, 1847–1853 (2019). https://doi.org/10.1016/S1872-2067(19)63411-X Tang, Y., Asokan, C., Xu, M., et al.: Rh single atoms on TiO2 dynamically respond to reaction conditions by adapting their site. Nat. Commun. 10, 4488 (2019). https://doi.org/10.1038/s41467-019-12461-6 Kodama, K., Jinnouchi, R., Takahashi, N., et al.: Activities and stabilities of Au-modified stepped-Pt single-crystal electrodes as model cathode catalysts in polymer electrolyte fuel cells. J. Am. Chem. Soc. 138, 4194–4200 (2016). https://doi.org/10.1021/jacs.6b00359 Chen, Z., Chen, Y.J., Chao, S.L., et al.: Single-atom AuI-N3 site for acetylene hydrochlorination reaction. ACS Catal. 10, 1865–1870 (2020). https://doi.org/10.1021/acscatal.9b05212 Cao, S.F., Yang, M., Elnabawy, A.O., et al.: Single-atom gold oxo-clusters prepared in alkaline solutions catalyse the heterogeneous methanol self-coupling reactions. Nat. Chem. 11, 1098–1105 (2019). https://doi.org/10.1038/s41557-019-0345-3 Xi, W., Wang, K., Shen, Y.L., et al.: Dynamic co-catalysis of Au single atoms and nanoporous Au for methane pyrolysis. Nat. Commun. 11, 1919 (2020). https://doi.org/10.1038/s41467-020-15806-8 Tian, C.C., Zhang, H.Y., Zhu, X., et al.: A new trick for an old support: stabilizing gold single atoms on LaFeO3 perovskite. Appl. Catal. B Environ. 261, 118178 (2020). https://doi.org/10.1016/j.apcatb.2019.118178 Liu, D., Li, J.C., Shi, Q.R., et al.: Atomically isolated iron atom anchored on carbon nanotubes for oxygen reduction reaction. ACS Appl. Mater. Interfaces 11, 39820–39826 (2019). https://doi.org/10.1021/acsami.9b12054 Gao, Y., Cai, Z.W., Wu, X.C., et al.: Graphdiyne-supported single-atom-sized Fe catalysts for the oxygen reduction reaction: DFT predictions and experimental validations. ACS Catal. 8, 10364–10374 (2018). https://doi.org/10.1021/acscatal.8b02360 Hou, C.C., Zou, L.L., Sun, L.M., et al.: Single-atom iron catalysts on overhang-eave carbon cages for high-performance oxygen reduction reaction. Angew. Chem. Int. Ed. 59, 7384–7389 (2020). https://doi.org/10.1002/anie.202002665 Li, J.C., Tang, D.M., Hou, P.X., et al.: The effect of carbon support on the oxygen reduction activity and durability of single-atom iron catalysts. MRS Commun. 8, 1158–1166 (2018). https://doi.org/10.1557/mrc.2018.174 Gole, J.L., White, M.G.: Nanocatalysis: selective conversion of ethanol to acetaldehyde using mono-atomically dispersed copper on silica nanospheres. J. Catal. 204, 249–252 (2001). https://doi.org/10.1006/jcat.2001.3335 Hajifatheali, H., Ahmadi, E., Wojtczak, A., et al.: The synthesis of N-methylbis[2-(dodecylthio)ethyl]amine (SNS) and investigation of its efficiency as new mononuclear catalyst complex in copper-based ATRP. Macromol. Res. 23, 977–985 (2015). https://doi.org/10.1007/s13233-015-3132-z Qin, L., Cui, Y.Q., Deng, T.L., et al.: Highly stable and active Cu1/CeO2 single-atom catalyst for CO oxidation: a DFT study. ChemPhysChem 19, 3346–3349 (2018). https://doi.org/10.1002/cphc.201800860 Zhao, C.M., Dai, X.Y., Yao, T., et al.: Ionic exchange of metal-organic frameworks to access single nickel sites for efficient electroreduction of CO2. J. Am. Chem. Soc. 139, 8078–8081 (2017). https://doi.org/10.1021/jacs.7b02736 Ling, C.Y., Shi, L., Ouyang, Y.X., et al.: Nanosheet supported single-metal atom bifunctional catalyst for overall water splitting. Nano Lett. 17, 5133–5139 (2017). https://doi.org/10.1021/acs.nanolett.7b02518 Dai, X.Y., Chen, Z., Yao, T., et al.: Single Ni sites distributed on N-doped carbon for selective hydrogenation of acetylene. Chem. Commun. 53, 11568–11571 (2017). https://doi.org/10.1039/c7cc04820c Cao, X.R., Ji, Y.F., Luo, Y.: Dehydrogenation of propane to propylene by a Pd/Cu single-atom catalyst: insight from first-principles calculations. J. Phys. Chem. C 119, 1016–1023 (2015). https://doi.org/10.1021/jp508625b Marcinkowski, M.D., Yuk, S.F., Doudin, N., et al.: Low-temperature oxidation of methanol to formaldehyde on a model single-atom catalyst: Pd atoms on Fe3O4(001). ACS Catal. 9, 10977–10982 (2019). https://doi.org/10.1021/acscatal.9b03891 Zhou, S.Q., Shang, L., Zhao, Y.X., et al.: Pd single-atom catalysts on nitrogen-doped graphene for the highly selective photothermal hydrogenation of acetylene to ethylene. Adv. Mater. 31, 1900509 (2019). https://doi.org/10.1002/adma.201900509 Liang, J.X., Lin, J., Yang, X.F., et al.: Theoretical and experimental investigations on single-atom catalysis: Ir1/FeOx for CO oxidation. J. Phys. Chem. C 118, 21945–21951 (2014). https://doi.org/10.1021/jp503769d Lu, Y.B., Kuo, C.T., Kovarik, L., et al.: A versatile approach for quantification of surface site fractions using reaction kinetics: the case of CO oxidation on supported Ir single atoms and nanoparticles. J. Catal. 378, 121–130 (2019). https://doi.org/10.1016/j.jcat.2019.08.023 Wang, Q., Huang, X., Zhao, Z.L., et al.: Ultrahigh-loading of Ir single atoms on NiO matrix to dramatically enhance oxygen evolution reaction. J. Am. Chem. Soc. 142, 7425–7433 (2020). https://doi.org/10.1021/jacs.9b12642 Du, Z.Z., Chen, X.J., Hu, W., et al.: Cobalt in nitrogen-doped graphene as single-atom catalyst for high-sulfur content lithium-sulfur batteries. J. Am. Chem. Soc. 141, 3977–3985 (2019). https://doi.org/10.1021/jacs.8b12973 Kim, K., Kang, T., Kim, M., et al.: Three-dimensional entangled and twisted structures of nitrogen doped poly-(1,4-diethynylbenzene) chain combined with cobalt single atom as a highly efficient bifunctional electrocatalyst. Appl. Catal. B Environ. 275, 119107 (2020). https://doi.org/10.1016/j.apcatb.2020.119107 Mori, K., Taga, T., Yamashita, H.: Isolated single-atomic Ru catalyst bound on a layered double hydroxide for hydrogenation of CO2 to formic acid. ACS Catal. 7, 3147–3151 (2017). https://doi.org/10.1021/acscatal.7b00312 Wang, D.W., Li, Q., Han, C., et al.: Single-atom ruthenium based catalyst for enhanced hydrogen evolution. Appl. Catal. B Environ. 249, 91–97 (2019). https://doi.org/10.1016/j.apcatb.2019.02.059 Schwerdtfeger, E.D., Irwin, L.J., Miller, S.A.: Highly branched polyethylene from ethylene alone via a single zirconium-based catalyst. Macromolecules 41, 1080–1085 (2008). https://doi.org/10.1021/ma702213c Yang, F., Song, P., Liu, X.Z., et al.: Highly efficient CO2 electroreduction on ZnN4-based single-atom catalyst. Angew. Chem. Int. Ed. 57, 12303–12307 (2018). https://doi.org/10.1002/anie.201805871 Guan, J.Q., Duan, Z.Y., Zhang, F.X., et al.: Water oxidation on a mononuclear manganese heterogeneous catalyst. Nat. Catal. 1, 870–877 (2018). https://doi.org/10.1038/s41929-018-0158-6 Kong, N.N., Fan, X., Liu, F.F., et al.: Single vanadium atoms anchored on graphitic carbon nitride as a high-performance catalyst for non-oxidative propane dehydrogenation. ACS Nano 14, 5772–5779 (2020). https://doi.org/10.1021/acsnano.0c00659 Saini, P.K., Romain, C., Williams, C.K.: Dinuclear metal catalysts: improved performance of heterodinuclear mixed catalysts for CO2-epoxide copolymerization. Chem. Commun. 50, 4164–4167 (2014). https://doi.org/10.1039/c3cc49158g Zhang, W.Y., Chao, Y.G., Zhang, W.S., et al.: Emerging dual-atomic-site catalysts for efficient energy catalysis. Adv. Mater. 33, 2102576 (2021). https://doi.org/10.1002/adma.202102576 Shi, Q., Ji, Y.J., Chen, W.X., et al.: Single-atom Sn–Zn pairs in CuO catalyst promote dimethyldichlorosilane synthesis. Natl. Sci. Rev. 7, 600–608 (2019). https://doi.org/10.1093/nsr/nwz196 Bai, L.C., Hsu, C.S., Alexander, D.T.L., et al.: A cobalt-iron double-atom catalyst for the oxygen evolution reaction. J. Am. Chem. Soc. 141, 14190–14199 (2019). https://doi.org/10.1021/jacs.9b05268 Fan, M.M., Cui, J.W., Wu, J.J., et al.: Improving the catalytic activity of carbon-supported single atom catalysts by polynary metal or heteroatom doping. Small 16, 1906782 (2020). https://doi.org/10.1002/smll.201906782 Zhang, L.L., Wang, A.Q., Miller, J.T., et al.: Efficient and durable Au alloyed Pd single-atom catalyst for the Ullmann reaction of aryl chlorides in water. ACS Catal. 4, 1546–1553 (2014). https://doi.org/10.1021/cs500071c Pei, G.X., Liu, X.Y., Yang, X.F., et al.: Performance of Cu-alloyed Pd single-atom catalyst for semihydrogenation of acetylene under simulated front-end conditions. ACS Catal. 7, 1491–1500 (2017). https://doi.org/10.1021/acscatal.6b03293 Wang, W.L., Santos, E.J.G., Jiang, B., et al.: Direct observation of a long-lived single-atom catalyst chiseling atomic structures in graphene. Nano Lett. 14, 450–455 (2014). https://doi.org/10.1021/nl403327u Alexopoulos, K., Vlachos, D.G.: Surface chemistry dictates stability and oxidation state of supported single metal catalyst atoms. Chem. Sci. 11, 1469–1477 (2020). https://doi.org/10.1039/c9sc05944j Yang, X.F., Wang, A.Q., Qiao, B.T., et al.: Single-atom catalysts: a new frontier in heterogeneous catalysis. Acc. Chem. Res. 46, 1740–1748 (2013). https://doi.org/10.1021/ar300361m Lai, W.H., Miao, Z.C., Wang, Y.X., et al.: Atomic-local environments of single-atom catalysts: synthesis, electronic structure, and activity. Adv. Energy Mater. 9, 1900722 (2019). https://doi.org/10.1002/aenm.201900722 Wang, B., Cai, H.R., Shen, S.H.: Single metal atom photocatalysis. Small Methods 3, 1800447 (2019). https://doi.org/10.1002/smtd.201800447 Zheng, N.F., Zhang, T.: Preface: single-atom catalysts as a new generation of heterogeneous catalysts. Natl. Sci. Rev. 5, 625–625 (2018). https://doi.org/10.1093/nsr/nwy095 Wang, Y., Bao, S.X., Li, R., et al.: Universal strategy for homogeneously doping noble metals into cyano-bridged coordination polymers. ACS Appl. Mater. Interfaces 7, 2088–2096 (2015). https://doi.org/10.1021/am508246m Lyu, D.D., Mollamahale, Y.B., Huang, S.L., et al.: Ultra-high surface area graphitic Fe–N–C nanospheres with single-atom iron sites as highly efficient non-precious metal bifunctional catalysts towards oxygen redox reactions. J. Catal. 368, 279–290 (2018). https://doi.org/10.1016/j.jcat.2018.10.025 Wang, J., Li, Z.J., Wu, Y.E., et al.: Fabrication of single-atom catalysts with precise structure and high metal loading. Adv. Mater. 30, e1801649 (2018). https://doi.org/10.1002/adma.201801649 Yan, H., Su, C.L., He, J., et al.: Single-atom catalysts and their applications in organic chemistry. J. Mater. Chem. A 6, 8793–8814 (2018). https://doi.org/10.1039/c8ta01940a Zhang, Q.Q., Guan, J.Q.: Single-atom catalysts for electrocatalytic applications. Adv. Funct. Mater. 30, 2000768 (2020). https://doi.org/10.1002/adfm.202000768 Qi, J.L., Xu, Q.Q., Sun, J.F., et al.: Synthesis, characterization and analysis of graphene-supported single-atom catalysts. Prog. Chem. 32, 505–518 (2020) Wu, W.H., Lei, W., Wang, L.Q., et al.: Preparation of single atom catalysts. Prog. Chem. 32, 23–32 (2020). https://doi.org/10.7536/PC190704 Alarawi, A., Ramalingam, V., He, J.H.: Recent advances in emerging single atom confined two-dimensional materials for water splitting applications. Mater. Today Energy 11, 1–23 (2019). https://doi.org/10.1016/j.mtener.2018.10.014 Guo, W.X., Wang, Z.Y., Wang, X.Q., et al.: General design concept for single-atom catalysts toward heterogeneous catalysis. Adv. Mater. 33, 2004287 (2021). https://doi.org/10.1002/adma.202004287 Zou, L.L., Wei, Y.S., Hou, C.C., et al.: Single-atom catalysts derived from metal–organic frameworks for electrochemical applications. Small 17, 2004809 (2021). https://doi.org/10.1002/smll.202004809 Xiong, H.F., Datye, A.K., Wang, Y.: Thermally stable single-atom heterogeneous catalysts. Adv. Mater. 33, 2004319 (2021). https://doi.org/10.1002/adma.202004319 Han, B., Lang, R., Qiao, B.T., et al.: Highlights of the major progress in single-atom catalysis in 2015 and 2016. Chin. J. Catal. 38, 1498–1507 (2017). https://doi.org/10.1016/S1872-2067(17)62872-9 Zhu, Y.Z., Peng, W.C., Li, Y., et al.: Modulating the electronic structure of single-atom catalysts on 2D nanomaterials for enhanced electrocatalytic performance. Small Methods 3, 1800438 (2019). https://doi.org/10.1002/smtd.201800438 Gawande, M.B., Fornasiero, P., Zbořil, R.: Carbon-based single-atom catalysts for advanced applications. ACS Catal. 10, 2231–2259 (2020). https://doi.org/10.1021/acscatal.9b04217 Abbet, S., Sanchez, A., Heiz, U., et al.: Acetylene cyclotrimerization on supported size-selected Pdn clusters (1 \(\leqslant\) n \(\leqslant\) 30): one atom is enough! J. Am. Chem. Soc. 122, 3453–3457 (2000). https://doi.org/10.1021/ja9922476 Tyo, E.C., Vajda, S.: Catalysis by clusters with precise numbers of atoms. Nat. Nanotechnol. 10, 577–588 (2015). https://doi.org/10.1038/nnano.2015.140 Johnson, G.E., Priest, T., Laskin, J.: Charge retention by gold clusters on surfaces prepared using soft landing of mass selected ions. ACS Nano 6, 573–582 (2012). https://doi.org/10.1021/nn2039565 Laskin, J., Johnson, G.E., Prabhakaran, V.: Soft landing of complex ions for studies in catalysis and energy storage. J. Phys. Chem. C 120, 23305–23322 (2016). https://doi.org/10.1021/acs.jpcc.6b06497 Chen, Y.J., Ji, S.F., Chen, C., et al.: Single-atom catalysts: synthetic strategies and electrochemical applications. Joule 2, 1242–1264 (2018). https://doi.org/10.1016/j.joule.2018.06.019 Vajda, S., White, M.G.: Catalysis applications of size-selected cluster deposition. ACS Catal. 5, 7152–7176 (2015). https://doi.org/10.1021/acscatal.5b01816 Jin, Y.Y., Hao, P.P., Ren, J., et al.: Single atom catalysis: concept, method and application. Prog. Chem. 27, 1689–1704 (2015) Liu, J.Y.: Catalysis by supported single metal atoms. ACS Catal. 7, 34–59 (2017). https://doi.org/10.1021/acscatal.6b01534 Dasgupta, N.P., Li, L., Sun, X.L.: Atomic layer deposition for energy and environmental applications. Adv. Mater. Interfaces 3, 1600914 (2016). https://doi.org/10.1002/admi.201600914 O’Neill, B.J., Jackson, D.H.K., Lee, J., et al.: Catalyst design with atomic layer deposition. ACS Catal. 5, 1804–1825 (2015). https://doi.org/10.1021/cs501862h Wang, H.W., Lu, J.L.: Atomic layer deposition: a gas phase route to bottom-up precise synthesis of heterogeneous catalyst. Acta Phys. Chim. Sin. 34, 1334–1357 (2018). https://doi.org/10.3866/pku.whxb201804201 Zhang, N.Q., Li, L.C., Huang, X., et al.: Research progress of single-atom catalysis. J. Chin. Soc. Rare Earths 36, 513–532 (2018) Cheng, N.C., Sun, X.L.: Single atom catalyst by atomic layer deposition technique. Chin. J. Catal. 38, 1508–1514 (2017). https://doi.org/10.1016/S1872-2067(17)62903-6 Wang, C.L., Gu, X.-K., Yan, H., et al.: Water-mediated Mars–van Krevelen mechanism for CO oxidation on ceria supported single-atom Pt1 catalyst. ACS Catal. 7, 887–891 (2016). https://doi.org/10.1021/acscatal.6b02685 Yan, H., Lv, H.F., Yi, H., et al.: Understanding the underlying mechanism of improved selectivity in Pd1 single-atom catalyzed hydrogenation reaction. J. Catal. 366, 70–79 (2018). https://doi.org/10.1016/j.jcat.2018.07.033 Yan, H., Cheng, H., Yi, H., et al.: Single-atom Pd1/graphene catalyst achieved by atomic layer deposition: remarkable performance in selective hydrogenation of 1,3-butadiene. J. Am. Chem. Soc. 137, 10484–10487 (2015). https://doi.org/10.1021/jacs.5b06485 Jiang, C.J., Shang, Z.Y., Liang, X.H.: Chemoselective transfer hydrogenation of nitroarenes catalyzed by highly dispersed, supported nickel nanoparticles. ACS Catal. 5, 4814–4818 (2015). https://doi.org/10.1021/acscatal.5b00969 Sun, S.H., Zhang, G.X., Gauquelin, N., et al.: Single-atom catalysis using Pt/graphene achieved through atomic layer deposition. Sci. Rep. 3, 1775 (2013). https://doi.org/10.1038/srep01775 Lang, R., Xi, W., Liu, J.C., et al.: Non defect-stabilized thermally stable single-atom catalyst. Nat. Commun. 10, 234 (2019). https://doi.org/10.1038/s41467-018-08136-3 Jones, J., Xiong, H.F., DeLaRiva, A.T., et al.: Thermally stable single-atom platinum-on-ceria catalysts via atom trapping. Science 353, 150–154 (2016). https://doi.org/10.1126/science.aaf8800 Cui, X.J., Dai, X.C., Surkus, A.E., et al.: Zinc single atoms on N-doped carbon: an efficient and stable catalyst for CO2 fixation and conversion. Chin. J. Catal. 40, 1679–1685 (2019). https://doi.org/10.1016/S1872-2067(19)63316-4 Zhao, S.Y., Cheng, Y., Veder, J.P., et al.: One-pot pyrolysis method to fabricate carbon nanotube supported Ni single-atom catalysts with ultrahigh loading. ACS Appl. Energy Mater. 1, 5286–5297 (2018). https://doi.org/10.1021/acsaem.8b00903 Yang, H.B., Hung, S.F., Liu, S., et al.: Atomically dispersed Ni(I) as the active site for electrochemical CO2 reduction. Nat. Energy 3, 140–147 (2018). https://doi.org/10.1038/s41560-017-0078-8 Jiao, L., Yang, W.J., Wan, G., et al.: Single-atom electrocatalysts from multivariate metal–organic frameworks for highly selective reduction of CO2 at low pressures. Angew. Chem. Int. Ed. 59, 20589–20595 (2020). https://doi.org/10.1002/anie.202008787 Cheon, J.Y., Kim, T., Choi, Y., et al.: Ordered mesoporous porphyrinic carbons with very high electrocatalytic activity for the oxygen reduction reaction. Sci. Rep. 3, 2715 (2013). https://doi.org/10.1038/srep02715 Yi, J.D., Xu, R., Wu, Q., et al.: Atomically dispersed iron-nitrogen active sites within porphyrinic triazine-based frameworks for oxygen reduction reaction in both alkaline and acidic media. ACS Energy Lett. 3, 883–889 (2018). https://doi.org/10.1021/acsenergylett.8b00245 Sa, Y.J., Seo, D.J., Woo, J., et al.: A general approach to preferential formation of active Fe–Nx sites in Fe–N/C electrocatalysts for efficient oxygen reduction reaction. J. Am. Chem. Soc. 138, 15046–15056 (2016). https://doi.org/10.1021/jacs.6b09470 Cheng, Y., He, S., Lu, S.F., et al.: Iron single atoms on graphene as nonprecious metal catalysts for high-temperature polymer electrolyte membrane fuel cells. Adv. Sci. 6, 1802066 (2019). https://doi.org/10.1002/advs.201802066 Derevyannikova, E.A., Kardash, T.Y., Stadnichenko, A.I., et al.: Structural insight into strong Pt–CeO2 interaction: from single Pt atoms to PtOx clusters. J. Phys. Chem. C 123, 1320–1334 (2019). https://doi.org/10.1021/acs.jpcc.8b11009 Jan, A., Shin, J., Ahn, J., et al.: Promotion of Pt/CeO2 catalyst by hydrogen treatment for low-temperature CO oxidation. RSC Adv. 9, 27002–27012 (2019). https://doi.org/10.1039/c9ra05965b Zhu, Y.F., Kong, X., Yin, J.Q., et al.: Covalent-bonding to irreducible SiO2 leads to high-loading and atomically dispersed metal catalysts. J. Catal. 353, 315–324 (2017). https://doi.org/10.1016/j.jcat.2017.07.030 Zheng, T.Q., Zhou, W., Gao, Y., et al.: Active impregnation method for copper foam as catalyst support for methanol steam reforming for hydrogen production. Ind. Eng. Chem. Res. 58, 4387–4395 (2019). https://doi.org/10.1021/acs.iecr.8b05241 Feng, S.Q., Song, X.G., Ren, Z., et al.: La-stabilized, single-atom Ir/AC catalyst for heterogeneous methanol carbonylation to methyl acetate. Ind. Eng. Chem. Res. 58, 4755–4763 (2019). https://doi.org/10.1021/acs.iecr.8b05402 Yang, H.L., Liu, Q.G., Li, Y., et al.: Isolated single-atom ruthenium anchored on beta zeolite as an efficient heterogeneous catalyst for styrene epoxidation. ChemNanoMat 6, 1647–1651 (2020). https://doi.org/10.1002/cnma.202000394 Jiang, R.H., Liu, S.M., Li, L., et al.: Single Ir atoms anchored on ordered mesoporous WO3 are highly efficient for the selective catalytic reduction of NO with CO under oxygen-rich conditions. ChemCatChem 13, 1834–1846 (2021). https://doi.org/10.1002/cctc.202001784 Kwon, Y., Kim, T.Y., Kwon, G., et al.: Selective activation of methane on single-atom catalyst of rhodium dispersed on zirconia for direct conversion. J. Am. Chem. Soc. 139, 17694–17699 (2017). https://doi.org/10.1021/jacs.7b11010 Hai, X., Xi, S., Mitchell, S., et al.: Scalable two-step annealing method for preparing ultra-high-density single-atom catalyst libraries. Nat. Nanotechnol. 17, 174–181 (2022). https://doi.org/10.1038/s41565-021-01022-y Kaiser, S.K., Fako, E., Manzocchi, G., et al.: Nanostructuring unlocks high performance of platinum single-atom catalysts for stable vinyl chloride production. Nat. Catal. 3, 376–385 (2020). https://doi.org/10.1038/s41929-020-0431-3 Szilágyi, P.Á., Rogers, D.M., Zaiser, I., et al.: Functionalised metal–organic frameworks: a novel approach to stabilising single metal atoms. J. Mater. Chem. A 5, 15559–15566 (2017). https://doi.org/10.1039/C7TA03134C Liu, S.S., Tan, J.M., Gulec, A., et al.: Stabilizing single-atom and small-domain platinum via combining organometallic chemisorption and atomic layer deposition. Organometallics 36, 818–828 (2017). https://doi.org/10.1021/acs.organomet.6b00869 Sun, Q.M., Wang, N., Zhang, T.J., et al.: Zeolite-encaged single-atom rhodium catalysts: highly-efficient hydrogen generation and shape-selective tandem hydrogenation of nitroarenes. Angew. Chem. Int. Ed. 58, 18570–18576 (2019). https://doi.org/10.1002/anie.201912367 Yang, H.Z., Shang, L., Zhang, Q.H., et al.: A universal ligand mediated method for large scale synthesis of transition metal single atom catalysts. Nat. Commun. 10, 4585 (2019). https://doi.org/10.1038/s41467-019-12510-0 Gao, C., Chen, S.M., Wang, Y., et al.: Heterogeneous single-atom catalyst for visible-light-driven high-turnover CO2 reduction: the role of electron transfer. Adv. Mater. 30, 1704624 (2018). https://doi.org/10.1002/adma.201704624 Abdel-Mageed, A.M., Rungtaweevoranit, B., Parlinska-Wojtan, M., et al.: Highly active and stable single-atom Cu catalysts supported by a metal–organic framework. J. Am. Chem. Soc. 141, 5201–5210 (2019). https://doi.org/10.1021/jacs.8b11386 Razmjooei, F., Yu, J.H., Lee, H.Y., et al.: Single-atom iron-based electrocatalysts for high-temperature polymer electrolyte membrane fuel cell: organometallic precursor and pore texture tailoring. ACS Appl. Energy Mater. 3, 11164–11176 (2020). https://doi.org/10.1021/acsaem.0c02111 Zheng, Y., Qiao, S.Z.: Metal–organic framework assisted synthesis of single-atom catalysts for energy applications. Natl. Sci. Rev. 5, 626–627 (2018). https://doi.org/10.1093/nsr/nwy010 Oisaki, K., Li, Q.W., Furukawa, H., et al.: A metal–organic framework with covalently bound organometallic complexes. J. Am. Chem. Soc. 132, 9262–9264 (2010). https://doi.org/10.1021/ja103016y Fan, Y., Liu, S.G., Yi, Y., et al.: Catalytic nanomaterials toward atomic levels for biomedical applications: from metal clusters to single-atom catalysts. ACS Nano 15, 2005–2037 (2021). https://doi.org/10.1021/acsnano.0c06962 Rivera-Cárcamo, C., Serp, P.: Single atom catalysts on carbon-based materials. ChemCatChem 10, 5058–5091 (2018). https://doi.org/10.1002/cctc.201801174 Kim, M.S., Park, H., Won, S.O., et al.: Copper-halide polymer nanowires as versatile supports for single-atom catalysts. Small 15, 1903197 (2019). https://doi.org/10.1002/smll.201903197 Lin, R.H., Albani, D., Fako, E., et al.: Design of single gold atoms on nitrogen-doped carbon for molecular recognition in alkyne semi-hydrogenation. Angew. Chem. Int. Ed. 58, 504–509 (2019). https://doi.org/10.1002/anie.201805820 Li, Q.H., Chen, W.X., Xiao, H., et al.: Fe isolated single atoms on S, N codoped carbon by copolymer pyrolysis strategy for highly efficient oxygen reduction reaction. Adv. Mater. 30, 1800588 (2018). https://doi.org/10.1002/adma.201800588 Pan, Y., Chen, Y.J., Wu, K.L., et al.: Regulating the coordination structure of single-atom Fe-NxCy catalytic sites for benzene oxidation. Nat. Commun. 10, 4290 (2019). https://doi.org/10.1038/s41467-019-12362-8 Li, X.N., Huang, X., Xi, S.B., et al.: Single cobalt atoms anchored on porous N-doped graphene with dual reaction sites for efficient Fenton-like catalysis. J. Am. Chem. Soc. 140, 12469–12475 (2018). https://doi.org/10.1021/jacs.8b05992 Liu, J.H., Yang, L.M., Ganz, E.: Efficient and selective electroreduction of CO2 by single-atom catalyst two-dimensional TM-Pc monolayers. ACS Sustain. Chem. Eng. 6, 15494–15502 (2018). https://doi.org/10.1021/acssuschemeng.8b03945 Chen, X.F., Yan, J.M., Jiang, Q.: Single layer of polymeric metal-phthalocyanine: promising substrate to realize single Pt atom catalyst with uniform distribution. J. Phys. Chem. C 118, 2122–2128 (2014). https://doi.org/10.1021/jp411183h Abel, M., Clair, S., Ourdjini, O., et al.: Single layer of polymeric Fe-phthalocyanine: an organometallic sheet on metal and thin insulating film. J. Am. Chem. Soc. 133, 1203–1205 (2011). https://doi.org/10.1021/ja108628r He, X.H., He, Q., Deng, Y.C., et al.: A versatile route to fabricate single atom catalysts with high chemoselectivity and regioselectivity in hydrogenation. Nat. Commun. 10, 3663 (2019). https://doi.org/10.1038/s41467-019-11619-6 Pan, Y., Liu, S.J., Sun, K.A., et al.: A bimetallic Zn/Fe polyphthalocyanine-derived single-atom Fe–N4 catalytic site: a superior trifunctional catalyst for overall water splitting and Zn-air batteries. Angew. Chem. Int. Ed. 57, 8614–8618 (2018). https://doi.org/10.1002/anie.201804349 Wu, H.H., Li, H.B., Zhao, X.F., et al.: Highly doped and exposed Cu(I)–N active sites within graphene towards efficient oxygen reduction for zinc–air batteries. Energy Environ. Sci. 9, 3736–3745 (2016). https://doi.org/10.1039/c6ee01867j Wu, K.L., Chen, X., Liu, S.J., et al.: Porphyrin-like Fe–N4 sites with sulfur adjustment on hierarchical porous carbon for different rate-determining steps in oxygen reduction reaction. Nano Res. 11, 6260–6269 (2018). https://doi.org/10.1007/s12274-018-2149-y Yang, H.Z., Shi, R., Shang, L., et al.: Recent advancements of porphyrin-like single-atom catalysts: synthesis and applications. Small Struct. 2, 2100007 (2021). https://doi.org/10.1002/sstr.202100007 Zheng, Y., Jiao, Y., Zhu, Y.H., et al.: Molecule-level g-C3N4 coordinated transition metals as a new class of electrocatalysts for oxygen electrode reactions. J. Am. Chem. Soc. 139, 3336–3339 (2017). https://doi.org/10.1021/jacs.6b13100 Ren, C.J., Jiang, Q.Y., Lin, W., et al.: Density functional theory study of single-atom V, Nb, and Ta catalysts on graphene and carbon nitride for selective nitrogen reduction. ACS Appl. Nano Mater. 3, 5149–5159 (2020). https://doi.org/10.1021/acsanm.0c00512 Chen, Y.J., Ji, S.F., Sun, W.M., et al.: Discovering partially charged single-atom Pt for enhanced anti-Markovnikov alkene hydrosilylation. J. Am. Chem. Soc. 140, 7407–7410 (2018). https://doi.org/10.1021/jacs.8b03121 Liu, L.M., Wang, N., Zhu, C.Z., et al.: Direct imaging of atomically dispersed molybdenum that enables location of aluminum in the framework of zeolite ZSM-5. Angew. Chem. Int. Ed. 59, 819–825 (2020). https://doi.org/10.1002/anie.201909834 Davis, M.E.: Ordered porous materials for emerging applications. Nature 417, 813–821 (2002). https://doi.org/10.1038/nature00785 Masoumifard, N., Guillet-Nicolas, R., Kleitz, F.: Synthesis of engineered zeolitic materials: from classical zeolites to hierarchical core-shell materials. Adv. Mater. 30, 1704439 (2018). https://doi.org/10.1002/adma.201704439 Guzman, J., Gates, B.C.: Supported molecular catalysts: metal complexes and clusters on oxides and zeolites. Dalton Trans. 17, 3303–3318 (2003). https://doi.org/10.1039/b303285j Zhang, W.J., Jiang, P.P., Wang, Y., et al.: Bottom-up approach to engineer a molybdenum-doped covalent-organic framework catalyst for selective oxidation reaction. RSC Adv. 4, 51544–51547 (2014). https://doi.org/10.1039/c4ra09304f Zhong, W.F., Sa, R.J., Li, L.Y., et al.: A covalent organic framework bearing single Ni sites as a synergistic photocatalyst for selective photoreduction of CO2 to CO. J. Am. Chem. Soc. 141, 7615–7621 (2019). https://doi.org/10.1021/jacs.9b02997 Huang, N., Wang, P., Jiang, D.L.: Covalent organic frameworks: a materials platform for structural and functional designs. Nat. Rev. Mater. 1, 16068 (2016). https://doi.org/10.1038/natrevmats.2016.68 Ramalingam, V., Varadhan, P., Fu, H.C., et al.: Heteroatom-mediated interactions between ruthenium single atoms and an MXene support for efficient hydrogen evolution. Adv. Mater. 31, 1903841 (2019). https://doi.org/10.1002/adma.201903841 Fu, Q., Li, W.X., Yao, Y.X., et al.: Interface-confined ferrous centers for catalytic oxidation. Science 328, 1141–1144 (2010). https://doi.org/10.1126/science.1188267 Côté, A.P., Benin, A.I., Ockwig, N.W., et al.: Porous, crystalline, covalent organic frameworks. Science 310, 1166–1170 (2005). https://doi.org/10.1126/science.1120411 Zhang, J.Q., Zhao, Y.F., Guo, X., et al.: Single platinum atoms immobilized on an MXene as an efficient catalyst for the hydrogen evolution reaction. Nat. Catal. 1, 985–992 (2018). https://doi.org/10.1038/s41929-018-0195-1 Peng, Y., Lu, B.Z., Chen, S.W.: Carbon-supported single atom catalysts for electrochemical energy conversion and storage. Adv. Mater. 30, 1801995 (2018). https://doi.org/10.1002/adma.201801995 Jiao, L., Jiang, H.L.: Metal–organic-framework-based single-atom catalysts for energy applications. Chem 5, 786–804 (2019). https://doi.org/10.1016/j.chempr.2018.12.011 Liao, T., Kou, L.Z., Du, A.J., et al.: Simplest MOF units for effective photodriven hydrogen evolution reaction. J. Am. Chem. Soc. 140, 9159–9166 (2018). https://doi.org/10.1021/jacs.8b04599 Sun, X.P., Sun, S.X., Gu, S.Q., et al.: High-performance single atom bifunctional oxygen catalysts derived from ZIF-67 superstructures. Nano Energy 61, 245–250 (2019). https://doi.org/10.1016/j.nanoen.2019.04.076 Hou, C.C., Wang, H.F., Li, C.X., et al.: From metal–organic frameworks to single/dual–atom and cluster metal catalysts for energy applications. Energy Environ. Sci. 13, 1658–1693 (2020). https://doi.org/10.1039/c9ee04040d Yang, L.M., Zeng, Y.C., Tang, X.J., et al.: Self-sacrificial template synthesis of a nitrogen-doped microstructured carbon tube as electrocatalyst for oxygen reduction. ChemElectroChem 5, 3731–3740 (2018). https://doi.org/10.1002/celc.201801050 Xiao, F., Xu, G.L., Sun, C.J., et al.: Nitrogen-coordinated single iron atom catalysts derived from metal organic frameworks for oxygen reduction reaction. Nano Energy 61, 60–68 (2019). https://doi.org/10.1016/j.nanoen.2019.04.033 Ji, S.F., Chen, Y.J., Zhao, S., et al.: Atomically dispersed ruthenium species inside metal–organic frameworks: combining the high activity of atomic sites and the molecular sieving effect of MOFs. Angew. Chem. Int. Ed. 58, 4271–4275 (2019). https://doi.org/10.1002/anie.201814182 Jiang, R., Li, L., Sheng, T., et al.: Edge-site engineering of atomically dispersed Fe–N4 by selective C–N bond cleavage for enhanced oxygen reduction reaction activities. J. Am. Chem. Soc. 140, 11594–11598 (2018). https://doi.org/10.1021/jacs.8b07294 Park, K.S., Ni, Z., Côté, A.P., et al.: Exceptional chemical and thermal stability of zeolitic imidazolate frameworks. PNAS 103, 10186–10191 (2006). https://doi.org/10.1073/pnas.0602439103 Xiao, M.L., Zhu, J.B., Li, G.R., et al.: A single-atom iridium heterogeneous catalyst in oxygen reduction reaction. Angew. Chem. Int. Ed. 58, 9640–9645 (2019). https://doi.org/10.1002/anie.201905241 Wang, X.J., Zhang, H.G., Lin, H.H., et al.: Directly converting Fe-doped metal–organic frameworks into highly active and stable Fe–N–C catalysts for oxygen reduction in acid. Nano Energy 25, 110–119 (2016). https://doi.org/10.1016/j.nanoen.2016.04.042 Merzougui, B., Hachimi, A., Akinpelu, A., et al.: A Pt-free catalyst for oxygen reduction reaction based on Fe–N multiwalled carbon nanotube composites. Electrochim. Acta 107, 126–132 (2013). https://doi.org/10.1016/j.electacta.2013.06.016 Zhang, H.G., Hwang, S., Wang, M.Y., et al.: Single atomic iron catalysts for oxygen reduction in acidic media: particle size control and thermal activation. J. Am. Chem. Soc. 139, 14143–14149 (2017). https://doi.org/10.1021/jacs.7b06514 Han, A.J., Wang, B.Q., Kumar, A., et al.: Recent advances for MOF-derived carbon-supported single-atom catalysts. Small Methods 3, 1800471 (2019). https://doi.org/10.1002/smtd.201800471 Xuan, N.N., Chen, J.H., Shi, J.J., et al.: Single-atom electroplating on two dimensional materials. Chem. Mater. 31, 429–435 (2019). https://doi.org/10.1021/acs.chemmater.8b03796 Su, X., Yang, X.F., Huang, Y.Q., et al.: Single-atom catalysis toward efficient CO2 conversion to CO and formate products. Acc. Chem. Res. 52, 656–664 (2019). https://doi.org/10.1021/acs.accounts.8b00478 Pan, Y., Lin, R., Chen, Y.J., et al.: Design of single-atom Co-N5 catalytic site: a robust electrocatalyst for CO2 reduction with nearly 100% CO selectivity and remarkable stability. J. Am. Chem. Soc. 140, 4218–4221 (2018). https://doi.org/10.1021/jacs.8b00814 Chen, L.W., Wu, Z.Y., Nan, H., et al.: A metal-catalyzed thermal polymerization strategy toward atomically dispersed catalysts. Chem. Commun. 55, 11579–11582 (2019). https://doi.org/10.1039/c9cc05975j Zhang, M.L., Wang, Y.G., Chen, W.X., et al.: Metal (hydr)oxides@polymer core–shell strategy to metal single-atom materials. J. Am. Chem. Soc. 139, 10976–10979 (2017). https://doi.org/10.1021/jacs.7b05372 Li, J., Liu, P., Tang, Y.Z., et al.: Single-atom Pt-N3 sites on the stable covalent triazine framework nanosheets for photocatalytic N2 fixation. ACS Catal. 10, 2431–2442 (2020). https://doi.org/10.1021/acscatal.9b04925 Ren, Z., Liu, Y., Lyu, Y., et al.: Single-atom Rh based bipyridine framework porous organic polymer: a high active and superb stable catalyst for heterogeneous methanol carbonylation. J. Catal. 369, 249–256 (2019). https://doi.org/10.1016/j.jcat.2018.11.015 Wang, D.H., Ao, C.C., Liu, X.K., et al.: Coordination-engineered Cu-Nx single-site catalyst for enhancing oxygen reduction reaction. ACS Appl. Energy Mater. 2, 6497–6504 (2019). https://doi.org/10.1021/acsaem.9b01066 Yang, H.P., Wu, Y., Li, G.D., et al.: Scalable production of efficient single-atom copper decorated carbon membranes for CO2 electroreduction to methanol. J. Am. Chem. Soc. 141, 12717–12723 (2019). https://doi.org/10.1021/jacs.9b04907 Qin, R.X., Liu, P.X., Fu, G., et al.: Strategies for stabilizing atomically dispersed metal catalysts. Small Methods 2, 1700286 (2018). https://doi.org/10.1002/smtd.201700286 Chen, L.F., Yang, T., Cui, H., et al.: A porous metal–organic cage constructed from dirhodium paddle-wheels: synthesis, structure and catalysis. J. Mater. Chem. A 3, 20201–20209 (2015). https://doi.org/10.1039/c5ta05592j Kou, Z.K., Zang, W.J., Ma, Y.Y., et al.: Cage-confinement pyrolysis route to size-controlled molybdenum-based oxygen electrode catalysts: from isolated atoms to clusters and nanoparticles. Nano Energy 67, 104288 (2020). https://doi.org/10.1016/j.nanoen.2019.104288 Zhang, H.J., Kawashima, K., Okumura, M., et al.: Colloidal Au single-atom catalysts embedded on Pd nanoclusters. J. Mater. Chem. A 2, 13498–13508 (2014). https://doi.org/10.1039/c4ta01696c Shi, Z.S., Yang, W.Q., Gu, Y.T., et al.: Metal-nitrogen-doped carbon materials as highly efficient catalysts: progress and rational design. Adv. Sci. 7, 2001069 (2020). https://doi.org/10.1002/advs.202001069 Wang, J., Liao, T., Wei, Z.Z., et al.: Heteroatom-doping of non-noble metal-based catalysts for electrocatalytic hydrogen evolution: an electronic structure tuning strategy. Small Methods 5, 2000988 (2021). https://doi.org/10.1002/smtd.202000988 Xi, J.B., Jung, H.S., Xu, Y., et al.: Single-atom catalysts: synthesis strategies, catalytic applications, and performance regulation of single-atom catalysts. Adv. Funct. Mater. 31, 2170081 (2021). https://doi.org/10.1002/adfm.202170081 Zhao, H.Y., Zhang, C.X., Li, H., et al.: One-dimensional nanomaterial supported metal single-atom electrocatalysts: synthesis, characterization, and applications. Nano Sel. 2, 2072–2111 (2021). https://doi.org/10.1002/nano.202100083 Calle-Vallejo, F., Koper, M.T.M.: Theoretical considerations on the electroreduction of CO to C2 species on Cu(100) electrodes. Angew. Chem. Int. Ed. 52, 7282–7285 (2013). https://doi.org/10.1002/anie.201301470 Schouten, K.J.P., Qin, Z.S., Pérez Gallent, E., et al.: Two pathways for the formation of ethylene in CO reduction on single-crystal copper electrodes. J. Am. Chem. Soc. 134, 9864–9867 (2012). https://doi.org/10.1021/ja302668n Vijay, S., Ju, W., Brückner, S., et al.: Unified mechanistic understanding of CO2 reduction to CO on transition metal and single atom catalysts. Nat. Catal. 4, 1024–1031 (2021). https://doi.org/10.1038/s41929-021-00705-y