Law, Zhi PinZhi PinLawSitdikovit, KantikaKantikaSitdikovitChao, Hsiao-YuanHsiao-YuanChaoKim-Lohsoontorn, PattarapornPattarapornKim-LohsoontornWen-Yueh Yu2026-02-092026-02-092026-06-0509263373https://www.scopus.com/record/display.uri?eid=2-s2.0-105027635388&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/735889Low-temperature methanol synthesis from CO2 hydrogenation has been achieved using ethanol as the catalytic solvent, which reacts with formate (forms from CO2 hydrogenation) to produce ethyl formate, a reactive intermediate that could hydrogenolyze into methanol under milder conditions. In this study, Cu/ZnO and Cu/CeO2 catalysts were compared for the methanol synthesis from ethanol-assisted CO2 hydrogenation. Reaction testing shows that the formation of ethyl formate favors on Cu/CeO2, whereas the conversion of ethyl formate to methanol prefers on Cu/ZnO. A series of ternary Cu/ZnO/CeO2 catalysts were rationally prepared and evaluated for ethanol-assisted CO2 hydrogenation. It is demonstrated that the methanol yield could be enhanced by tuning the Ce/(Ce+Zn) ratio of Cu/ZnO/CeO2 catalysts. The optimum methanol yield is achieved as a result of the balanced abilities of esterification of formate with ethanol and hydrogenolysis of ethyl formate with hydrogen, which is in line with the Sabatier principle. In-situ infrared spectroscopy reveals that with exposure to the CO2-H2 gas mixture, the bridged formate forms on both Cu/CeO2 and Cu/ZnO, after which converts into ethyl formate via esterification upon ethanol introduction. On Cu/CeO2, ethyl formate strongly binds to the surface oxygen vacancy, stabilizing in an η1-(O) adsorption geometry. In contrast, ethyl formate adsorbs on Cu/ZnO in a form of η2-(C,O) geometry, which readily converts into methanol via ester bond cleavage and hydrogenolysis. The findings in this study may serve as a guideline for the rational design of heterogeneous catalysts for low-temperature methanol synthesis.falseCO2 hydrogenationCu-based catalystsIn-situ infrared spectroscopyMethanolOxygen vacancyjournal article10.1016/j.apcatb.2026.1264432-s2.0-105027635388