Insights into facet-dependent reactivity of CuO–CeO2 nanocubes and nanorods as catalysts for CO oxidation reaction

In this study, we deposited 1 wt% Cu on mostly {100}-exposed CeO2 nanocubes (1CuCe NC) and mostly {110}-exposed CeO2 nanorods (1CuCe NR), respectively. Both 1CuCe NC and 1CuCe NR have been used as catalysts for the oxidation of CO and achieved 100% and 50% CO conversion at 130 °C, respectively. The differences in the catalytic activity of 1CuCe NC and 1CuCe NR were analyzed using temperature-programmed reduction of H2 and temperature-programmed desorption of CO techniques. The results confirmed the excellent reducibility of the 1CuCe NC catalyst, which was attributed to the weak interactions between Cu and the CeO2 support. Moreover, in situ diffuse reflectance infrared Fourier-transform spectroscopy studies indicated that the {100} planes of 1CuCe NC facilitated the generation of active Cu(I) sites, which resulted in the formation of highly reactive Cu(I)-CO species during the oxidation of CO. Both the excellent redox properties and effective CO adsorption capacity of the 1CuCe NC catalyst increased its catalytic reactivity.Graphical AbstractThe presence of abundant Cu(I) site expedites the adsorption of CO on 1CuCe NC {100} owing to the formation of Cu(I)-CO species; consequently, the facile CO2 desorption contributes to the catalytic performance of 1CuCe NC {100} being superior to that of 1CuCe NR {110}.
Source: Chinese Journal of Catalysis - Category: Chemistry Source Type: research