Freeze-dried Co3O4–CeO2 catalysts for the preferential oxidation of CO with the presence of CO2 and H2O in the feed

Abstract

A synthesis method in two steps was used to obtain Co3O4–CeO2 (COCE) catalysts. Firstly, freeze-drying precursors to obtain a submicrometric ceria powders support were calcined at a temperature as low as 400°C. Then, the support was impregnated with a Co(II) acetate solution by incipient wetness impregnation, varying the loading of Co between 5 and 20wt%, and calcined again at 400°C. xCOCE samples were tested for the preferential oxidation of CO in a H2-rich stream (CO-PROX). All samples showed catalytic activity and high selectivity towards CO2 at low reaction temperatures, being 15COCE the most active catalyst. Moreover, simulating a CO-PROX unit operation, the influence of the presence of CO2 and H2O in the feed was tested, showing a high activity and selectivity mainly to CO2.