How CO2 Chemisorption States Affect Hydrogenation Activity
How CO2 Chemisorption States Affect Hydrogenation Activity
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DOI：
10.1021/acs.iecr.9b01316
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发表时间：
2019-05
影响因子：
4.2
通讯作者：
Bin Yang;Lijun Wang;Zile Hua;Limin Guo
中科院分区：
文献类型：
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作者：
Bin Yang;Lijun Wang;Zile Hua;Limin Guo
二氧化碳（CO2）活化然后加氢是实现有效控制CO2排放的替代途径。对于活化，中性CO2分子首先在催化剂上化学吸附为羧酸盐（CO2δ−）或碳酸盐（CO 32-），这是一个重要的步骤。迄今为止，CO2化学吸附状态与加氢活性之间关系的阐明尚缺乏直接的实验证据。为此，我们研制了Zn-Cr复合氧化物催化剂模型。通过原位DRIFTS实验对催化剂的化学吸附状态和加氢机理进行了研究。此外，额外的表征表明，CO2化学吸附状态取决于表面氧浓度和物种。结合CO2加氢实验结果，得出羧酸盐化学吸附态有利于提高加氢活性的结论。
Carbon dioxide (CO2) activation and then hydrogenation is an alternative route to achieve the efficient control of CO2 emission. For activation, the neutral CO2 molecule is first chemisorbed as carboxylate (CO2δ−) or carbonate (CO32–) on catalysts, which is an important step. Up to now, the relationship elucidation between CO2 chemisorption states and hydrogenation activity still lacks of direct experimental evidence. Herein, the model Zn–Cr mixed oxide catalysts were created to fulfill the goal. The chemisorption states and hydrogenation mechanism were carefully identified by in situ DRIFTS experiments. Furthermore, additional characterizations demonstrated that CO2 chemisorption states depended on surface oxygen concentration and species. Combined with the results of CO2 hydrogenation experiments, the conclusion that chemisorption state as carboxylate was beneficial for higher hydrogenation activity was concluded.