Low Temperature CO Oxidation Over a Novel Nano-Structured, Mesoporous CeO 2 Supported Au Catalyst

Highly active, nano-structured, mesoporous CeO2 (CN) supported Au catalysts have been studied for low temperature catalytic CO oxidation. These catalysts were synthesized by first synthesizing the CeO2 support via chitosan template process followed by 1 wt% Au incorporation using precipitation-deposition method. A complete CO conversion into CO2 was achieved at room temperature over Au–CeO2 (A-CN-110) catalyst with a specific rate of 2.65 molCO.gAu −1 h−1. The A-CN- 110 catalyst treated under different oxidation and reduction atmosphere was also very active at room temperature. The CO oxidation activity of CN based materials was also compared with commercial CeO2 (C) supported catalysts, as well as those reported in the literature. The catalysts were characterized in detail using p-XRD, BET-SA, ICP-OES, SEM, XPS, EDX, H2- TPR, O2- TPD, and HR-TEM techniques. The structure property relationship clearly demonstrates that the key factors for superior catalytic activity are; reducible nature of support/improved defects ( Ce3+), lower crystallite size, and high surface area. Oxidation state, nature of dispersion, and particle size of Au also influences the catalytic activity. Strongly bound gold nano-particles with ceria surface assist the reducibility of the surface oxygen, which enhances the catalytic activity.