关键词: CO₂加氢, 甲醇, 双金属氧化物, 固定床, 氧空位

Abstract:

The catalytic conversion of CO₂ to methanol using green hydrogen generated from renewable energy sources is a promising path toward carbon neutrality.The catalyst employed in the CO₂ hydrogenation to methanol technology is a ZnO-CeO₂ bimetallic oxide.Various preparation methods such as impregnation，co-precipitation，precipitation coating，and physical mixing were investigated.Characterization techniques including X-ray diffraction（XRD），N₂ adsorption-desorption，carbon dioxide temperature-programmed desorption（CO₂-TPD），hydrogen temperature-programmed desorption（H₂-TPD），scanning electron microscopy（SEM），and X-ray photoelectron spectroscopy（XPS） were utilized to analyze the physicochemical properties of the ZnO-CeO₂ bimetallic oxide catalyst and its impact on the catalytic performance in CO₂ hydrogenation to methanol.The results indicated that the preparation method significantly influenced the physicochemical properties and catalytic performance of the catalyst.The ZnO-CeO₂ catalyst prepared by co-precipitation exhibited excellent catalytic performance.Under reaction conditions of temperature of 300 ℃，pressure of 4 MPa，and weight hourly space velocity of 19 600 mL/（g·h），the CO₂ conversion rate reached 4.61%，methanol selectivity achieved 80.64%，and the methanol space-time yield reached 244.96 mg/（h·g）.It was observed that high concentration of oxygen vacancies，strong H₂ activation capability，large specific surface area，and pore volume were crucial for enhancing the catalytic performance of this catalyst.

Key words: CO₂ hydrogenation, methanol, bimetallic oxide, fixed bed, oxygen vacancy