Dual-reaction pathway engineering via anode-driven methanol oxidation for efficient electrocatalytic ammonia production

Abstract

Replacing the anodic oxygen evolution reaction with selective methanol oxidation to formic acid offers a promising route to enhance paired electrochemical ammonia synthesis. However, the inherent kinetic and thermodynamic disparities between the cathodic reduction reaction and anodic oxidation reaction present significant challenges in achieving optimal electrochemical system performance. Herein, we propose a dual-reaction strategy employing bifunctional Au/CoOOH nanocomposite catalysts, achieving simultaneous NH₃ production (34.15 g) and formic acid synthesis (69.65 g) after 24 h at 2.6 V cell voltage. Density functional theory (DFT) calculations further reveal that loading in Co-based catalysts and its hybridization with Au nanoparticles can effectively tune the electronic configuration of the Co-O sites to poison their strong adsorption capacity of intermediate products, lowering the reaction energy barrier to alter the reaction pathway. This work provides an atomic-level design principle for coupled electrochemical systems, demonstrating better reaction efficiency, while co-producing high-value chemicals for scalable green ammonia synthesis.