Facile Synthesis of a Nonprecious Metal Catalyst for Efficient Electrocatalytic Conversion of CO ₂ to Dimethyl Carbonate

We report a nickel nanoparticle-embedded porous carbon catalyst (Ni NPs/C) derived from one-step pyrolysis of a nickel-based metal–organic framework for tandem electrochemical CO 2 -to-dimethyl carbonate (DMC) conversion. The catalyst features small Ni nanoparticles (∼15 nm) with an ultrahigh loading of 91 wt %, dispersed within a hierarchical microporous-mesoporous carbon matrix. This architecture enables efficient mass/electron transfer and promotes effective utilization of the active sites, leading to a DMC production rate of 285 μmol cm –2 h –1 with 42% Faradaic efficiency under ambient conditions, along with stable operation over 24 h. Density functional theory calculations reveal that the Ni-carbon synergy stabilizes the *COOH intermediate while facilitating CO desorption. In situ FTIR spectroscopy directly captures both *COOH and the subsequent *CH 3 OCOO – intermediate, providing evidence for the coupled electroreduction–methoxycarbonylation pathway. This work establishes a mechanistically informed, nonprecious metal catalytic system for sustainable CO 2 valorization, offering a scalable strategy for tandem electrocatalyst design.