Tailoring Coordination Fields of Asymmetric MO₅S₁‐Type Metal–Organic Frameworks Catalysts for Accelerated Oxygen Evolution Reaction

Abstract

Asymmetric coordination has emerged as a promising approach to enhance the oxygen evolution reaction (OER) activity, yet achieving a controlled synthesis of asymmetric structures to comprehensively understand the structure‐activity relationship remains challenging. In this study, a facile and effective symmetry‐breaking strategy is reported for tailoring the asymmetric MO5S1‐type metal–organic frameworks (MOFs) catalyst, establishing the correlation between the sulfur (S)‐mediated electron rearrangement and the adsorption/desorption dynamics of oxygen‐related intermediates in OER. Experimental and theoretical calculations reveal that a well‐designed asymmetric structure can effectively lower the d‐band center, optimizing the adsorption behavior of OH* and significantly decreasing the reaction energy barrier for the rate‐determining step (OH* → O*) with enhanced O–H bond cleavage process. The S‐NiFe‐MOF/CFP catalyst demonstrates a remarkable OER performance in an alkaline electrolyte environment. More importantly, the self‐assembled anion exchange membrane water electrolysis cell showcases a low voltage of 1.84 V to deliver the current density of 1 A cm−2, maintaining long‐term stability for over 100 h. This study unveils a precise asymmetric synthesis strategy employing S, highlighting the critical role of manipulating electron redistribution through asymmetric coordination to promote catalytic activity and develop advanced MOF‐based catalysts.