采用等体积浸渍法制备了Ni/Al₂O₃、2Mn-Ni/Al₂O₃、2Ce-Ni/Al₂O₃和2Mn-2Ce-Ni/Al₂O₃催化剂。利用XRD、H₂-TPR、BET、H₂-化学吸附、CO₂-TPD等对催化剂进行表征。结果表明，Mn和Ce作为双金属助剂具有协同效应，显著减弱Ni与载体的相互作用，提高活性金属的分散度和表面积，增加对CO₂的吸附，降低反应温度。CO₂甲烷化活性测试结果表明，Mn和Ce及Mn-Ce助剂的掺入提高了催化剂的CO₂转化率和CH₄选择性，2Mn-2Ce-Ni/Al₂O₃催化剂性能最佳，在较低温度就表现出高活性。2Mn-2Ce-Ni/Al₂O₃催化剂在600℃耐热后活性保持不变，具有良好的耐热性能。当反应温度为300℃、压力为0.75 MPa、空速为6 000 mL/（g·h）时，CO₂转化率和CH₄选择性分别达到96.2%和99.6%。

Ni/Al₂O₃,2Mn-Ni/Al₂O₃,2Ce-Ni/Al₂O₃ and 2Mn-2Ce-Ni/Al₂O₃ catalysts are prepared by the co-impregnation method.Characterization analysis on these catalysts shows that Mn and Ce have synergistic effects as bimetallic promoter,significantly reducing the interaction between Ni species and the support,increasing the dispersion and surface area of active metals,increasing the adsorption amount to CO₂,and lowering the reaction temperature.Test results for CO₂ methanation activity show that the addition of Mn,Ce,and Mn-Ce promoters improves CO₂ conversion rate and CH₄ selectivity over the catalyst.2Mn-2Ce-Ni/Al₂O₃ catalyst has the best performance among these catalysts,showing a high activity even at a lower temperature.2Mn-2Ce-Ni/Al₂O₂ catalyst has a good heat resistance,its activity remains unchanged after heat resistance at 600℃.Higher pressure is helpful to promote methanation reaction.CO₂ conversion and CH₄ selectivity reach 96.2% and 99.6%,respectively when reaction temperature is at 300℃,pressure is 0.75 MPa,and space velocity is 6 000 mL·g^-1·h^-1.

杨帆(1995-),男,硕士研究生,研究方向为CO₂加氢甲烷化工艺,947889697@qq.com