f–π* Back‐Bonding Orbital Induced by a Lutetium‐Based Conducting Metal–Organic Framework Promotes Highly Selective CO <sub>2</sub> ‐to‐CH <sub>4</sub> Conversion at Low Potential
Fuqing Yu, Guangyao Zhang, Minxing Shu, Hongming Wang
Abstract
Abstract The research on electrocatalytic carbon dioxide reduction (ECR) catalysts using renewable energy is particularly crucial in energy conversion studies, especially for viable hydrocarbon production. This study employs density functional theory calculations to screen a series of non‐radioactive lanthanide two‐dimensional metal–organic frameworks (MOFs) for product selectivity in ECR. Based on theoretical screening, our focus is on a lutetium (Lu)‐based conducting MOF (Lu‐HHTP), which exhibits a Faradaic efficiency of approximately 77 % for methane (CH 4 ) production and maintains a stable current density of −280 mA/cm 2 at −1.1 V vs. RHE. In situ electrochemical experiments and material characterization demonstrate that the Lu sites possess high coordination stability and structural recoverability during catalytic CO 2 reduction, attributed to the overlap between Lu′s f‐orbitals and the π*‐orbitals of the ligand O, and the formation of back bonding orbitals between the f‐orbitals of Lu and the π* orbitals of CO contribute increasing CH 4 selectivity and lowering the potential. This study leverages rare‐earth MOF‐type materials, offering a novel approach to addressing low conductivity and stabilizing rare‐earth materials, thereby establishing a theoretical framework for the conversion of linearly adsorbed *CO into hydrocarbons.