Novel PtCuO/CeO2/α-Al2O3 sponge catalysts for the preferential oxidation of CO (PROX) prepared by means of supercritical fluid reactive deposition (SFRD)

Ceramic sponges (α-alumina) supporting ceria wash-coats and PtCuO layers of varying compositions were tested in the preferential oxidation (PROX) of CO in the presence of excess hydrogen. Copper and platinum were loaded simultaneously on the ceria-coated sponge by means of supercritical fluid reactive deposition (SFRD) which includes adsorption and reduction of metal-organic complexes dissolved in supercritical CO2. Products were characterized by means of SEM, STEM HAADF, EDX, H2-TPR, CO-TPD, CO2-TPD and N2-adsorption. Catalysts prepared after the SFRD-method exhibit high selectivity. The CO oxidation activity roughly correlates with the copper content and is superior as compared to the activity of PROX-catalysts reported in the literature so far.