Preferential oxidation of CO in excess H2 over CuO/CeO2 catalysts: Characterization and performance as a function of the exposed face present in the CeO2 support

Structure/activity relationships on the basis of multitechnique characterization and catalytic testing complemented by operando-DRIFTS analysis for the preferential oxidation of CO in H2-rich streams demonstrate interactions of dispersed CuO with CeO2 (100) faces in ceria nanocubes as most interesting for the process. [Display omitted] ► CO-PROX catalytic properties of CuO/CeO2 as a function of the exposed face in CeO2. ► Ceria nanocubes supported system shows most interesting CO-PROX performance. ► Redox and particle size properties of dispersed CuO particles appear most relevant. A series of oxidised copper-cerium nanostructured catalysts prepared by impregnation of copper over ceria supports synthesized by different methods (hydrothermal with varying preparation parameters, microemulsion/precipitation), in order to achieve different specific morphologies (nanocubes, nanorods and nanospheres), have been examined with respect to their catalytic properties for preferential oxidation of CO in excess H2 (CO-PROX). The catalysts have been characterized in detail by XRD, Raman, SBET measurement, HREM, XPS, TPR and EPR, which allows establishing a model of structural characteristics of the catalysts. The characterization results have been correlated with analysis of CO-PROX catalytic properties by means of catalytic activity measurements complemented by operando-DRIFTS. Structural dependence of the CO oxidation reaction on the dispersed copper oxide entities as a function of the exposed face present at the surface of the different ceria supports is revealed. An important overall enhancement of the CO-PROX performance is detected for the sample supported on ceria nanocubes which is proposed to be a consequence of the interaction between copper oxide and (100) faces of the ceria support.