Theoretical study of the mechanism of methanol oxidation on PtNi catalyst

Abstract The anodic methanol oxidation reaction (MOR) generates a toxic intermediate CO in direct methanol fuel cell (DMFC), where the Pt catalyst is easily deactivated and the catalytic activity will be inevitably lowered. Alloying modification is an important approach to improve the anti-CO ability of Pt catalyst. In this work, MOR mechanism on PtNi catalyst is theoretically studied on four crystal planes doped with one-to-three Ni atoms. The main path of CO poisoning on the catalyst surface: CH3OH→CH2OH→CHOH→CHO→CO was studied. Meanwhile, the adsorption of PtNi catalyst on the reaction intermediate was carried out. Based on the relative energy ΔE, the four optimal catalysts were compared for MOR. Building on the above comprehensive evaluations the appropriate catalysts were finally selected by the activation effect. It is proved by calculation that the selected 1,2,3Ni-Pt (200) reduces the relative energy of the overall reaction path, possessing good catalytic effect on MOR with certain anti-CO toxicity.