Abstract:

The effect of metal Ni modification on the activity of Cu/CeO₂ catalyst for CO₂ hydrogenation to methanol is investigated. The catalyst structure before and after modification is characterized by XRD, BET, XPS, H₂-TPR, etc. The results show that the specific surface area of Cu/CeO₂ is the largest at a metal loading of 20%. A Cu to Ni mass ratio of 3∶1 results in the largest catalyst alkalinity, the largest oxygen vacancy content, and the strongest Cu-Ni synergism. The catalyst shows a superior reaction effect of CO₂ hydrogenation to methanol at a reaction temperature of 240 ℃, a reaction pressure of 3 MPa, a space velocity of 2,400 mL/(g·h), and an H₂ to CO₂ volume ratio of 3∶1, with a CO₂ conversion of 18.5% and a methanol space time yield of 40.43 g/(kg·h).

Key words: CO₂, hydrogenation, methanol, Cu/CeO₂ catalyst, reaction condition, conversion rate, selectivity, space time yield

摘要：

考察了第二金属Ni改性对CO₂加氢制甲醇Cu/CeO₂催化剂活性的影响，并通过XRD、BET、XPS、H₂-TPR等手段对改性前后催化剂结构进行了表征。结果表明：金属负载量为20%时，Cu/CeO₂的比表面积最大；Cu与Ni质量比为3∶1时，催化剂碱度最大，氧空位含量最高，Cu-Ni协同作用最强；该催化剂在反应温度240℃、反应压力3 MPa、液时空速2 400 mL/(g·h)、H₂与CO₂体积比为3∶1时催化CO₂加氢制甲醇效果较优，CO₂转化率为18.5%,甲醇时空产率为40.43 g/(kg·h)。

关键词: CO₂, 加氢, 甲醇, Cu/CeO₂催化剂, 反应条件, 转化率, 选择性, 时空产率