Fine-tuning the local coordination environment of atomic PtAu coupled with Pt clusters to enhance electrocatalytic...

Advancements in direct methanol fuel cells (DMFCs) have underscored the critical need for efficient electrocatalysts owing to sluggish methanol oxidation reaction (MOR) kinetics. The coupling of Au and Pt regulates Pt electronic structure, enhancing catalytic performance. To further optimize Pt catalytic performance and improve atomic utilization efficiency, we designed an active structure featuring heteronuclear PtAu atomic pairs coupled with Pt clusters. By carefully controlling the sequence of key synthesis steps, we successfully developed the Pt@Pt-Au/NC-2 catalyst, achieving an optimal mass activity of 4.77 Amg_Pt^-1 and specific activity of 4.57 mAcm^-2, outperforming commercial Pt/C catalysts by 5.81- and 3.20-fold, respectively. Additionally, the catalyst demonstrates exceptional CO tolerance, ensuring excellent long-term stability. Experimental findings integrated with density functional theory (DFT) calculations demonstrate that the electronic effects of the atomic PtAu pair enhance the CO oxidation rate and the synchronization of the hydroxide-mediated proton coupled electron transfer (HM-PCET) process, thereby facilitating the methanol oxidation reaction. This research not only emphasizes the precise synthesis of advanced atomically dispersed materials but also deepens the understanding of structure-performance relationships in multi-metallic catalytic systems, contributing to a wide range of its applications.