Insight Observation of Simultaneously Enhanced CO Tolerance and Stability of Pt Electrocatalysts Decorated with Oxygen Vacancy Rich Cerium Oxide

Abstract High and stable catalytic activity for the methanol oxidation reaction (MOR) and CO tolerance are essential for anodic electrocatalysts in direct methanol fuel cells (DMFCs). Here, we report a new method to simultaneously boost the CO tolerance as well as MOR stability of a Pt electrocatalyst by decoration with cerium oxide (CeOx). Detailed mechanistic investigations revealed that CeOx decoration can significantly improve the MOR stability of the Pt electrocatalyst due to the formation of Pt−O−Ce bonds ascribed to the high number of oxygen vacancies of CeOx. The simultaneously improved CO anti‐poisoning property of the CeOx decorated Pt electrocatalyst is resulting from Ce(OH)3, which is formed by the adsorption of water to CeOx. Ce(OH)3 could accelerate the formation of Pt(OH)ads species to recover CO poisoned Pt nanoparticles. At the same time, the CO species could also be oxidized by the lattice oxygen from CeOx. The fuel cell performance of the CeOx decorated Pt electrocatalyst is therefore higher than that of bare Pt electrocatalyst.