A. Aijaz1, Justus Masa2, Christoph Rösler3, Wei Xia1, Philipp Weide1, Alexander Botz2, Roland A. Fischer3, Wolfgang Schuhmann2, Martin Muhler1,4
1Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780 Bochum, Germany
2Analytical Chemistry—Center for Electrochemical Sciences (CES) Ruhr-University Bochum 44780 Bochum Germany
3Inorganic Chemistry II—Organometallics & Materials, Department of Chemistry and Biochemistry Ruhr-University Bochum 44780 Bochum Germany
4Max Planck Institute for Chemical Energy Conversion, 45470 Mülheim an der Ruhr, Germany
Tóm tắt
AbstractEfficient reversible oxygen electrodes for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are vitally important for various energy conversion devices, such as regenerative fuel cells and metal–air batteries. However, realization of such electrodes is impeded by insufficient activity and instability of electrocatalysts for both water splitting and oxygen reduction. We report highly active bifunctional electrocatalysts for oxygen electrodes comprising core–shell Co@Co3O4 nanoparticles embedded in CNT‐grafted N‐doped carbon‐polyhedra obtained by the pyrolysis of cobalt metal–organic framework (ZIF‐67) in a reductive H2 atmosphere and subsequent controlled oxidative calcination. The catalysts afford 0.85 V reversible overvoltage in 0.1 m KOH, surpassing Pt/C, IrO2, and RuO2 and thus ranking them among one of the best non‐precious‐metal electrocatalysts for reversible oxygen electrodes.
