Weak Bimetal Coupling-Assisted MN₄ Catalyst for Enhanced Carbon Dioxide Reduction Reaction

The design of multimetal catalysts holds immense significance for efficient CO₂ capture and its conversion into economically valuable chemicals. Herein, heterobimetallic catalysts (M_iM_o)L were exploited for the CO₂ reduction reactions (CO₂RR) using relativistic density functional theory (DFT). The octadentate Pacman-like polypyrrolic ligand (H₄L) accommodates two metal ions (Mo, W, Nd, and U) inside (M_i) and outside (M_o) its month, rendering a weak bimetal coupling-assisted MN₄ catalytically active site. Adsorption reactions have access to energetically stable coordination modes of -OCO, -OOC, and -(OCO)₂, where the donor atom(s) are marked in bold. Among all of the species, (U_iMo_o)L releases the most energy. Along CO₂RR, it favors to produce CO. The high-efficiency CO₂ reduction is attributed to the size matching of U with the ligand mouth and the effective manipulation of the electron density of both ligand and bimetals. The mechanism in which heterobimetals synergetically capture and reduce CO₂ has been postulated. This establishes a reference in elaborating on the complicated heterogeneous catalysis.