Enhanced Low-temperature CO₂ Hydrogenation to Methane Over Co-Zn Oxides Catalysts

In this work, Co_x/ZnO catalysts with different CoZn mass ratios were prepared by hydrothermal and impregnation methods, demonstrating that Co_x/ZnO exhibits excellent low temperature (<260°C) CO₂ methanation activity and selectivity at reaction pressures as low as 0.5Mpa. In order to explain the reaction properties of Co_x/ZnO at low temperature and low pressure, the physicochemical properties of the catalysts were characterized by H₂-TPR, XRD, BET, XPS and CO₂-TPD.The results show that, compared with pure Co₃O₄ and ZnO samples, when CoZn is involved in the catalyst, the interaction between CoZn improves the structural properties of the catalyst, increases the specific surface area, generates more oxygen vacancies in the Co_x/ZnO catalyst, and promotes the activation of CO₂.This makes the Co_x/ZnO catalyst have excellent performance of CO₂ methanation. At the reaction temperature of 260℃, the CO₂ conversion of Co₅/ZnO catalyst can reach 82.27%, and the selectivity of CH₄ and CO are 99.53% and 0.047%, respectively. It remained stable for 50 hours. This work highlights the interaction between CoZn and will contribute to the development of more effective low temperature and low pressure CO₂ hydrogenation catalysts.