How the balance between *CO and *H intermediates in dual atom catalysts boosts selectivity for hydrocarbons†

Abstract

Double atom catalysts (DACs) have long faced a significant gap between theoretical predictions and experimental performance in the field of electrocatalytic CO₂ reduction for the preparation of hydrocarbons. This study reveals through integrated electronic structure analysis and reaction kinetics simulation that the key mechanism constraining performance is the synergistic adsorption imbalance between *CO and *H intermediates. Innovative discoveries include: (1) breaking through the traditional single descriptor paradigm, proposing a bivariate regulation criterion for the adsorption energy difference between *CO and *H, and elucidating its dominant role in the coupling efficiency of *CO and *H; (2) the second metal induced d orbital reconstruction optimizes the adsorption strength by enhancing the occupation of *CO antibonding orbitals; (3) the bimetallic side bridging nitrogen atoms form specific proton transport channels due to the redistribution of charge density, opening up new pathways for H supply; (4) revealing the innovative mechanism of constructing in situ proton sources through water molecule coordination of IIIB/IVB metals, with significantly lower transition state energy barriers than traditional dissociation pathways. The design framework of “electronic structure adsorption equilibrium proton coupling” established in this work provides cross scale theoretical guidance for the active site engineering of diatomic catalysts.