Unravelling the support-dependent active structures and SO2-tolerance of supported Pt catalysts to remediate toxic CO contaminant: An experimental and theoretical perspective

Catalyst deactivation caused by SO 2 poisoning generally hinders commercial viability of CO oxidation catalysts in the field of industrial flue gas purification. XPS results, CO-DRIFTS spectra and DFT calculations suggested that Pt was highly-dispersed and remained the oxidative states on SnO 2 support, resulting in that the rate-determining step of CO oxidation is to clean up the adsorbed CO and PtS 2 species is readily formed in a SO 2 -contained hydrothermal environment. It predominantly maintained metallic Pt 0 in the Pt/WO 3 catalyst, thereby led to cleaning up the activated oxygen atoms as the rate-determining step. It is very difficult to remove the sulfur species in SO 2 -poisoned catalysts within 600 °C and the mechanisms of CO oxidation are not affected by SO 2 poisoning for Pt/SnO 2 and Pt/WO 3 catalysts. These findings provide some significant insights to understand the mechanisms of CO oxidation and SO 2 -tolerance.