Improvement in Low Temperature CO Oxidation Activity of CuOx/CeO2-δby Cs2O Doping: Mechanistic Aspects

The various wt% of Cs promoted CuOx/CeO(2-delta)catalysts were prepared by impregnation method and examined for CO oxidation. The 0.1 wt% Cs doped CuOx/CeO(2-delta)showed a maximum CO oxidation (22%) compared to the CuOx/CeO2-delta(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 Cs2O 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.