Dispersion, reduction and catalytic performance of CuO supported on ZrO2-doped TiO2 for NO removal by CO

CuO catalysts supported on ZrO2-doped TiO2 (hereafter denoted as TZ) and pure anatase TiO2 were characterized by HRTEM. XRD, UV-vis DRS, TPR, XPS. in situ FT-IR and activity test for the removal of NO by CO. The results indicate that: (1) CuO species can be highly dispersed on the surface of TZ support, and the dispersion capacity (DC) is about 1.1 mmol/100 m(2) TZ, which can be explained by the incorporation model. (2) The reduction temperature of CuO supported on TZ is lower than that supported on pure anatase TiO2, ZrO2 and ZrO2 surface-modified anatase TiO2 supports. Furthermore, the activity of Cu-TZ is also the highest among them measured by a relative turn over frequency (TOF) value of NO. (3) The ZrO2 doping into TiO2 improves the adsorption stability of NOx (especially the bridged nitrate/nitro) and decreases the active temperature of Cu+-CO species, both of which are the key intermediates for NO conversion. On the other hand, the ZrO2 doping into TiO2 promotes the formation of Cu+/Cu-0 species at high temperatures, which has a crucial effect on N2O reduction. (C) 2011 Elsevier B.V. All rights reserved.