Ga‐doped CeO2 solid solutions as promoters for Cu‐based catalysts: Enhancing CO2 hydrogenation to methanol via optimized metal–support interaction

Abstract The low methanol selectivity of Cu/CeO₂ in CO₂ hydrogenation stems from weak metal–support interaction (MSI) and dominant reverse water gas shift (RWGS) pathways. Ga‐doped CeO₂ solid solutions are proposed to enhance MSI and oxygen vacancies, addressing insufficient CO₂ activation and H₂ dissociation in conventional Cu‐based catalysts. CuO‐CeGaₓOₓ ( y = 0–0.3) catalysts were synthesized via co‐precipitation. Structural and catalytic properties were analyzed by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), temperature‐programmed H 2 reduction (H₂‐TPR), temperature‐programmed desorption of adsorbed CO 2 (CO₂‐TPD), and transmission electron microscopy (TEM). Ga doping ( y = 0.2) optimized CeGaOₓ solid solution formation, achieving the highest specific surface area (142 m 2 /g), and Cu 0 content (73.4%). At 260°C, CuO‐CeGa₀.₂Oₓ showed 12.6% X CO₂ , 57% S CH₃OH , and STY = 308.8 g MeOH Kgcat −1 h −1 . Enhanced oxygen vacancies and moderate basic sites suppressed RWGS, favouring methanol pathways. Stability tests confirmed 180 h performance retention without structural degradation. Ga doping strengthens MSI via CeGaOₓ solid solutions, promoting oxygen vacancies and Cu 0 dispersion. This dual optimization enhances CO₂ adsorption, H₂ dissociation, and methanol selectivity while suppressing CO byproducts. The CuO‐CeGa₀.₂Oₓ catalyst demonstrates industrial potential, offering a design strategy for high‐performance CO₂ hydrogenation catalysts.