Enhancing Electrocatalytic Methanol Oxidation on PtCuNi Core–Shell Alloy Structures in Acid Electrolytes
Qianqian Wu, Xin Huang, Tingting Wan, Dong Xiang, Xiaowu Li, Kun Wang, Xiaoyou Yuan, Peng Li, Manzhou Zhu
Abstract
A key challenge for direct methanol fuel cells is the sluggish reaction kinetics, poor anti-CO poisoning ability, and insufficient Pt utilization of platinum-based catalysts during methanol oxidation reaction (MOR). Herein, we report a facile approach for PtCuNi electrocatalysts with adjustable inner and surface configurations. By judiciously controlling the nucleation/growth kinetics, PtCuNi core-shell alloy nanoparticles (PtCuNi-CS NPs) fortified with a Cu-rich core and a Pt-rich shell are obtained. Especially, PtCuNi-CS NPs show the highest mass activity and specific activity toward MOR, 5.7 and 5.1 times higher than those of commercial Pt/C. Density functional theory calculations reveal that the PtCuNi-CS NPs with a suitable d-band center possess excellent electro-oxidation activity. Additionally, the doping of Cu and Ni atoms endows the PtCuNi-CS NPs with enhanced OH* adsorption. This work provides an effective design strategy to develop Pt-based trimetallic electrocatalysts as efficient anode materials for fuel cell applications.