Regulating the cobalt phthalocyanine molecules by introducing adjacent cubic molybdenum carbide nanoparticles for accelerated proton transfer towards efficient CO2 reduction reaction

Abstract Electrochemical CO2 reduction reaction (CO2RR) is an important application that can considerably mitigate environmental and energy crises. However, the slow proton-coupled electron transfer process continues to limit overall catalytic performance. Fine-tuning the reaction microenvironment by accurately constructing the local structure of catalysts provides a novel approach to enhancing reaction kinetics. Here, cubic-phase α-MoC1−x nanoparticles were incorporated into a carbon matrix and coupled with cobalt phthalocyanine molecules (α-MoC1−x–CoPc@C) for the co-reduction of CO2 and H2O, achieving an impressive Faradaic efficiency for CO close to 100%. Through a combination of in-situ spectroscopies, electrochemical measurements, and theoretical simulations, it is demonstrated that α-MoC1−x nanoparticles and CoPc molecules with the optimized local configuration serve as the active centers for H2O activation and CO2 reduction, respectively. The interfacial water molecules were rearranged, forming a dense hydrogen bond network on the catalyst surface. This optimized microenvironment at the electrode–electrolyte interface synergistically enhanced water dissociation, accelerated proton transfer, and improved the overall performance of CO2RR.