Efficient Catalysis for Acidic Methanol Oxidation: Exploration of a Low-Platinum Quaternary Alloy Catalyst Via a Two-Step Method

Abstract

Conventional platinum-based catalysts demonstrate suboptimal catalytic efficacy and durability during the methanol oxidation reaction (MOR), compounded by their elevated platinum content, which not only escalates the economic expenditure but also complicates the experimental protocols. To address this, we have developed an innovative low-platinum-loaded catalyst using a four-component alloy and a two-step method. This approach achieves the goal of significantly reducing the platinum content while maintaining excellent catalytic performance by precisely controlling the composition and structure of the alloy. The two-step synthesis methodology offers a streamlined alternative to the conventional multi-step processes, thereby augmenting the efficiency and reproducibility of catalyst preparation. This refined approach significantly reduces the procedural intricacies associated with traditional synthesis routes, facilitating a more consistent and dependable method for the production of catalyst materials. Experimental results indicate that the PtCoSnCu/N-C alloy catalyst demonstrates excellent catalytic activity in methanol solution, with a mass activity and specific activity of 3670.412 mA mg−1Pt and 6.53 mA cm−2, respectively, which are 9.73 and 9.75 times higher than that of commercial platinum on carbon (Pt/C) catalysts. Notably, the optimized PtCoSnCu/N-C alloy catalyst demonstrates superior long-term stability compared to Pt/C after aging and extended stability testing. Density functional theory (DFT) calculations further reveal the optimization of electronic structure and the synergistic effect of surface atoms in the PtCoSnCu/N-C catalyst, which helps to reduce the adsorption energy of CO molecules and improve the utilization rate of active sites during the oxidation process. This research presents a novel, low-platinum catalyst strategy for methanol fuel cells, setting a theoretical basis for catalyst design and optimization.

Keywords: Methanol Oxidation Reaction (MOR), Low-platinum-loaded catalyst, Streamlined alternative, Quaternary Alloy, Density functional theory (DFT) calculations