Versatile application of wet-oxidation for ambient CO abatement over Fe(OH)x supported subnanometer platinum group metal catalysts

Abstract

The efficient and stable abatement of CO pollutant under ambient conditions is of great significance; however, it remains a formidable challenge. Herein, we report the versatile application of wet oxidation over Fe(OH) x supported subnanometer Pt group metal (PGM) catalysts for the complete removal of CO under ambient temperature and humidity conditions. Typically, the 1.8 wt% Rh/Fe(OH) x catalyst exhibited better durability during a ∼1400 min run for wet oxidation than for dry CO oxidation. Multiple characterization results including HR-TEM, H 2 -TPR, and in-situ DRIFTS suggested that Fe(OH) x , with good reducibility, promoted by the subnanometer Rh clusters, provided sites for the adsorption and reaction of O 2 and H 2 O to form OH species. Subsequently, these OH species reacted with the adsorbed CO on Rh sites with a considerably lower activation energy (9 kJ mol −1 ) than that of dissociated O species (22 kJ mol −1 ), thus rationalizing the outstanding performance of Rh/Fe(OH) x for wet oxidation. Extended experiments with other PGMs revealed a good generality for the application of wet oxidation in the efficient abatement of CO under humid conditions with Fe(OH) x as the support. Versatile CO abatement under ambient conditions is achieved by wet-oxidation over Fe(OH) x supported subnanometer Pt group metal catalysts owing to the facile formation and reaction of hydroxyl groups.