Promoting Efficient Ethanol Oxidation via Multimetallic Synergy in PdPtNiBiCo Networks

Abstract

The commercialization of direct alcohol fuel cells (DAFCs) is severely hindered by sluggish anodic alcohol oxidation reaction kinetics and the high susceptibility of catalysts to deactivation. Traditional Pd/Pt-based catalysts suffer from difficult C−C bond cleavage and severe CO poisoning. To address these issues, we synthesize a pentametallic PdPtNiBiCo alloy consisting of interconnected nanoparticles via a facile one-pot oil-phase method, aiming to maximize electrochemically accessible surface sites and trigger robust multimetallic synergy. This architecture delivers an exceptional alkaline ethanol oxidation activity of 16.64 A mg−1Pd+Pt, 12 and 19 times higher than those of commercial Pd/C and Pt/C, respectively. Furthermore, the catalyst exhibits robust antipoisoning durability over 4000 cycles and broad activity for methanol and ethylene glycol oxidation. Density functional theory calculations reveal that multimetallic synergy effectively modulates the d-band center of the active sites. Density functional theory calculations reveal that multimetallic synergy tunes the electronic structure of the active sites, optimizes the adsorption of key intermediates, and lowers the thermodynamic energy requirements for C−C bond cleavage and CO oxidation, thereby facilitating both the C1 and C2 pathways of ethanol oxidation. This work addresses the key limitation of traditional Pd/Pt-based catalysts and provides an effective strategy for designing high-performance universal DAFC anodes.