Structure‐Sensitivity Switch on Mo ₂ CT _x MXene: Steering CO ₂ Hydrogenation via Surface Termination and Copper Coordination

Abstract

ABSTRACT The pursuit of precise product control in CO 2 hydrogenation represents a central challenge in catalysis, where the inherent complexity of reaction networks often obscures the fundamental connection between surface structure and catalytic selectivity. Here, by integrating density functional theory and microkinetic modeling, we systematically decouple the distinct roles of surface oxygen termination and Cu coordination geometry in regulating catalytic selectivity of Mo 2 CO x catalysts. We identify three structurally sensitive regimes: pristine Mo 2 CO x surfaces facilitate efficient C═O bond cleavage to form CO and CH 4 , with higher oxygen coverage enhancing CO selectivity and promoting CH 3 OH among hydrogenated products; Cu‐adsorbed Mo 2 CO x enhances CH 4 generation by maintaining C═O scission while suppressing CO desorption; and Cu‐doped Mo 2 CO x promotes CH 3 OH formation by reducing surface oxophilicity and stabilizing key oxygenated intermediates. Crucially, we establish the Cu oxidation state as a quantitative descriptor for CH 3 OH/CH 4 selectivity, with a higher valence favoring CH 3 OH production. These mechanistic insights, corroborated by in situ spectroscopy and catalytic tests, bridge structure sensitivity with macroscopic performance. This work establishes general design principles for selective CO 2 conversion on MXene‐based catalysts, providing a foundation for the rational design of advanced CO 2 hydrogenation systems.