Promotional Effect of Pt-Doping on the Catalytic Performance of Pt-CeO2 Catalyst for CO Oxidation

Growing interest in the development of a hydrogen economy means that CO oxidation is increasingly important for upgrading H-2-rich fuel gas streams for fuel cells. CeO2-supported catalysts are the most promising candidates for the catalytic oxidation of CO because of their high activity. In the present work, DFT+U calculations were performed to investigate the stability and CO oxidation reactivity of Pt-n (n = 1-4) clusters supported on CeO2(111) (Pt/CeO2) and Pt-doped CeO2(111) (Pt/(Pt-Ce)O-2) surfaces. The Pt clusters showed similar nucleation behavior on both CeO2 and (Pt-Ce)O-2 surfaces. Further, the formation of oxygen vacancies (O-v) was facilitated because of surface charge depletion caused by the dopant Pt. Our DFT results suggest that the interfacial O-V plays an important role in the CO oxidation reaction cycle, and the calculated energy barrier for the CO oxidation reaction on the Pt/(Pt-Ce)O-2 surface is approximately 0.43 eV lower than that on the surface of the undoped catalyst, suggesting enhanced CO oxidation reactivity. Therefore, the chemical modification of the CeO2 support via doping is an effective strategy for improving the catalytic performance of Pt/CeO2.

Automated summary

The oxidation of CO is important for upgrading H-2-rich fuel gas streams for fuel cells. This study investigates the stability and CO oxidation reactivity of Pt-n clusters supported on CeO2 and Pt-doped CeO2 surfaces. The results suggest that doping enhances the catalytic activity of Pt clusters.