Boosting C=O Bond Scissoring Over a Pyridinic Nitrogen-Modified Cu–MoC Interface for High-Efficiency CO2 Hydrogenation to CO

Abstract

Reverse water-gas shift (RWGS) reaction-aided sustainable CO₂ conversion has emerged as one promising and effective approach for simultaneously mitigating climate change and solidifying energy security. Molybdenum carbide-based catalysts demonstrate excellent selectivity for sustainably transforming CO₂ into CO product, but harsh carburization syntheses and insufficient catalytic activity and stability significantly hinder their related commercial applications. Herein, a facile “inside-out” synthesis strategy was proposed to fabricate dispersed Cu clusters on sub-2 nm α-MoC nanoislands confined in pyridinic nitrogen-doped carbon (Cu-MoC/NC). This catalyst achieves the highest CO₂ conversion rate of 2583.4 mmol_CO2 g_cat⁻¹ h⁻¹ compared to those of all reported Mo-based catalysts, and maintains excellent catalytic stability for 500 h under a low H₂ partial pressure. Combined with X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations, the electronegativity of pyridinic nitrogen intensifies the electron deficiency of α-MoC and strengthens the chemisorption of Cu clusters on α-MoC nanoislands surface, facilitating the electronic interaction and stability of Cu–MoC interface. This pyridinic nitrogen-modified Cu–MoC interface promotes the CO₂ bridged adsorption at the interface and thus boosts C=O bond scissoring, inducing the transition of rate-limiting step and energy barrier reduction of the key intermediates. This interfacial engineering provides a sustainable and efficient strategy for improving both catalytic activity and stability of RWGS reaction to transform CO₂ into value-added fuels and chemicals.