Ni/Mg‐Doped Ceria Interface Enhances Concentrated Solar‐Driven CO 2 Reduction With CH 4

Abstract

ABSTRACT Concentrated‐solar catalytic conversion of carbon dioxide (CO 2 ) offers a promising route to utilize greenhouse gases via renewable energy. Dry reforming of methane (DRM) is particularly attractive, converting both CO 2 and methane (CH 4 ) into valuable syngas (CO and H 2 ). However, its efficiency is limited by catalysts that cannot effectively couple light‐induced interfacial excitation with the activation of both reactants. Herein, we report a Ni catalyst supported on Mg‐doped ceria (NCM) that constructs a light‐responsive Ni/Mg‐Ce interface for concentrated‐solar catalysis. Mg incorporation contracts the CeO 2 lattice, narrows the band gap, promotes interfacial charge transfer, and stabilizes Ni species. In situ near‐ambient pressure X‐ray photoelectron spectroscopy （NAP‐XPS） and CO‐probe diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reveal that Mg doping enables light‐induced interfacial electronic redistribution. Experiments and theoretical calculations collectively elucidate that Mg‐induced interfacial tuning governs the kinetic process via electron‐coupled proton transfer under light irradiation during CO 2 reduction coupled with CH 4 dehydrogenation. Under concentrated‐solar catalysis, the NCM catalyst delivers H 2 and CO production rates of 44.3 and 51.7 mol g Ni −1 h −1 , respectively, along with a light‐to‐chemical energy efficiency of 8.5% and stable operation over 100 h. This work reveals the critical role of dopant‐engineered interfacial effects in driving the synergistic activation of CO 2 and CH 4 under concentrated‐solar catalysis, providing new insights into CO 2 conversion in artificial photosynthesis.