Balancing Reactant Adsorption for Ultra-Stable Electrocatalytic Methanol Oxidation Reaction

Abstract

The practical application of the electrocatalytic methanol oxidation reaction (EMOR) has long been hindered by the lack of active and stable catalysts. Herein, we report a unique dealloyed PtMn catalyst on carbon cloth (d-PtMn/CC) characterized by a compressively strained Pt surface and a Mn concentration-gradient core. This d-PtMn/CC catalyst demonstrates EMOR activity that is 7–14 times higher than that of conventional Pt/CC catalysts in all-pH electrolytes, while exhibiting exceptional resistance to catalytic poisoning over a broad potential range of 0.4 to 1.2 V vs. RHE. When employed in direct methanol fuel cells, it achieves 111.6 mW cm−2 for over 10 hours at ultralow 0.59 mgPt cm−2, substantially outperforming commercial Pt/C catalysts. Comparative analyses of adsorbed reactants/intermediates revealed that imbalanced adsorption of reactants on the catalyst surface is the primary cause of EMOR poisoning. The d-PtMn/CC catalyst, benefiting from surface compressive strain and ligand effects, maintains balanced reactant adsorption over the wide potential range, thereby achieving ultra-stable EMOR performance. These findings not only resolve the longstanding controversy regarding EMOR poisoning mechanism but also identify the effectiveness of the “ligand + surface strain” strategy in DMFCs, facilitating its practical applications.