Unraveling the Synergistic Dual-Active-Site and Redox Cycling Mechanisms in CoS@NiCo LDH for Enhanced Methanol Electrooxidation

Engineering electrocatalysts with tailored electronic structures is essential for achieving efficient methanol oxidation reactions (MOR), yet it remains a significant challenge. This work introduces a CoS@NiCo LDH nanoarray electrocatalyst created through a simple one-step method, exhibiting exceptional activity and durability via synergistic electronic modulation and dual-active-site catalysis.The <i>in situ</i> formed heterointerface between Co₃S₄ and NiCo LDH facilitates substantial electron redistribution, which significantly enhances charge transfer kinetics and optimizes the adsorption energy of key reaction intermediates. Additionally, <i>in situ</i> spectroscopic studies capture the dynamic redox cycling of Ni²⁺/Ni³⁺ and Co²⁺/Co³⁺ during MOR, revealing the fundamental mechanisms responsible for the accelerated reaction kinetics. The catalyst demonstrates exceptional performance, requiring only 1.42 V to achieve a current density of 100 mA cm^-2, while maintaining approximately 85% selectivity for formate over 41 h of continuous operation. Notably, when it is configured for methanol-assisted water electrolysis, the system produces high-purity hydrogen at a rate of 2608 μL min^-1 which is 3.4 times faster than conventional alkaline water electrolysis. This advancement allows for simultaneous production of valuable chemicals and energy-efficient hydrogen generation. This study offers both a mechanistic understanding and a practical design strategy for multifunctional electrocatalysts in integrated energy conversion systems.