Incorporation of Epoxy Carbon onto CeO₂-Supported Pt to Tackle the CO Self-Poisoning Issue

The catalytic oxidation of carbon monoxide (CO) under ambient conditions plays a crucial role in the abatement of indoor CO, which poses risks to human health. Despite the notable activity exhibited by Pt-based catalysts in CO oxidation, their efficacy is usually diminished by the CO self-poisoning issue. In this work, three different Pt/CeO₂-based catalysts, which have distinct coordinative environments of Pt but an identical Pt/CeO₂ substrate structure, were synthesized by activating the catalyst with CO using different temperatures and durations. Compared with clean and graphite-covered Pt on CeO₂, the one modified by epoxy carbon showed higher activity and stability. The combination of characterizations and density functional theory modeling demonstrated that the clean Pt on CeO₂ rapidly deactivated due to the CO self-poisoning albeit high initial activity, and conversely, low initial activity was observed for the more stable graphite-covered catalyst due to the obstruction of the Pt site. In contrast, epoxy carbon species on Pt shifted the d-band of Pt to lower energy, weakening the Pt-CO binding strength. Such a modification mitigated the self-poisoning effect while maintaining ample active sites and enabling the complete oxidative removal of CO under ambient conditions. This work may provide a general approach to tackling the self-poisoning issue.