The origin of the decline in the photocatalytic activity of TiO2 in the decomposition of NO: TPD spectra of the adsorbed NO species
Tóm tắt
In order to investigate the cause of the decline in the photocatalytic activity of TiO2 in the decomposition of NO in a flow reaction system, detailed TPD measurements of the photocatalysts were carried out after the photoreactions. It was found that the TPD peak assigned to the adsorbed NO species observed at around 524 K is directly associated with a decline in the photocatalytic activity. The TPD spectrum of the adsorbed NO species consisted of three different types of species. The γ-adsorbed species of NO, formed under UV irradiation on the active surface sites, was found to cause a remarkable decline in the photocatalytic activity of TiO2. It was also found that this decline could be recovered to its original activity by heat treatment with Ar and/or O2 at around 573 K.
Tài liệu tham khảo
M. Anpo and H. Yamashita, in: Surface Photochemistry, M. Anpo (Ed.), p. 117. Wiley, Chichester (1996).
M. Anpo, Catal. Surv. Jpn. 1, 169 (1997).
N. Serpone and E. Pelizzetti, Photocatalysis. Wiley, New York, NY (1989).
M. A. Fox and M. T. Dulay, Chem. Rev. 93, 341 (1993).
M. Anpo, Stud. Surf. Sci. Catal. 130, 157 (2000).
J. L. Zhang, M. Minagawa, T. Ayusawa, S. Natarajan, H. Yamashita, M. Matsuoka and M. Anpo, J. Phys. Chem. B 104, 11501 (2000).
H. Alekabi and N. Serpone, J. Phys. Chem . 92, 5726 (1988).
J. Fan and J. T. Yates, Jr., J. Am. Chem. Soc. 118, 4686 (1996).
H. Yamashita, M. Honda, M. Harada, Y. Ichihashi, M. Anpo, T. Hirao, N. Itoh and N. Iwamoto, J. Phys. Chem. B 102, 10707 (1998).
J. L. Zhang, T. Ayusawa, M. Minagawa, K. Kinugawa, H. Yamashita, M. Matsuoka and M. Anpo, J. Catal. 198, 1 (2001).
D. R. Park, J. L. Zhang, K. Ikeue, H. Yamashita and M. Anpo, J. Catal. 185, 114 (1999).
L. A. Phillips and G. B. Raupp, J. Mol. Catal. 77, 297 (1992).
T. N. Obee and R. T. Brown, Environ. Sci. Technol. 29, 1223 (1995).
S. A. Larson and J. L. Falconer, Catal. Lett. 44, 57 (1997).
H. Yamashita, Y. Ichihashi, M. Harada, G. Stewart, M. A. Fox and M. Anpo, J. Catal. 158, 97 (1996).
J. Peral and D. F. Ollis, J. Catal. 136, 554 (1992).
O. Hennezel and D. F. Ollis, J. Catal. 167, 118 (1997).
J. Cunningham and B. K. Hodnett, J. Chem. Soc., Faraday Trans. 1 77, 2777 (1981).
S. A. Larson and J. L. Falconer, Catal. Lett. 44, 57 (1997).
N. K. Pande and A. T. Bell, J. Catal. 97, 137 (1986).
T. Okuhara and M. Misono, Hyomen 28, 87 (1990).