Improvement in Low Temperature CO Oxidation Activity of CuOx/CeO2−δ by Cs2O Doping: Mechanistic Aspects

The various wt% of Cs promoted CuO x /CeO 2−δ catalysts were prepared by impregnation method and examined for CO oxidation. The 0.1 wt% Cs doped CuO x /CeO 2−δ showed a maximum CO oxidation (22%) compared to the CuO x /CeO 2−δ (9%) at light off temperature (40 ºC). The plausible CO oxidation mechanism has explained using characterization techniques like ATR-FTIR, XPS, XRD, SEM, H 2 -TPR, and HRTEM. The formation of Cs 2 O was responsible for the stabilization of Cu 1+ species. The Cs doping increases the electron density on the catalyst surface due to the charge diffusion. The Cs addition in CuCe leads to the formation of smaller Cu 1+ species, CuO nanorod, Ce 3+ and adsorbed oxygen. The role of these species for CO oxidation at a lower temperature is explained in detail with plausible mechanism. The synergistic interaction of Cs with CuCe leads to the increase in CO conversion rate with decrease in the activation energy.