Fe−Ni Diatomic Sites Coupled with Pt Clusters to Boost Methanol Electrooxidation via Free Radical Relaying

Abstract

AbstractPt‐based catalysts for direct methanol fuel cells (DMFCs) are still confronted with the challenge of over‐oxidation of Pt and poisoning effect of intermediates; therefore, a spatial relay strategy was adopted to overcome these issues. Herein, Pt clusters were creatively fixed on the N‐doped carbon matrix with rich Fe−Ni diatoms, which can provide independent reaction sites for methanol oxidation reaction (MOR) and enhance the catalytic activity due to the electronic regulation effect between Pt cluster and atomic‐level metal sites. The optimized Pt/FeNi−NC catalyst shows MOR electrocatalytic activity of 2.816 A mgPt−1, 2.6 times that of Pt/C (1.115 A mgPt−1). Experiments combined with DFT study reveal that Fe−Ni diatoms and Pt clusters take charge of hydroxyl radical (⋅OH) generation and methanol activation, respectively. The free radical relaying of ⋅OH could prevent the over‐oxidation of Pt. Meanwhile, ⋅OH from Fe−Ni sites accelerates the elimination of intermediates, thus improving the durability of catalysts.