通过水热法制备了Ce/Zr摩尔比分别为1：19、1：9、2：8、3：7的铈锆复合物，利用微型高压反应釜考察了在160℃、3.5 MPa下4种催化剂对CO₂和甲醇直接合成碳酸二甲酯（DMC）的催化性能，并利用XRD、N₂吸附-脱附、FT-IR、NH₃-TPD和CO₂-TPD对其进行表征。结果表明，Ce的加入没有改变单斜ZrO₂的晶相，Ce/Zr摩尔比为2：8（Ce_0.2ZrO₂）时表现出优异的催化性能，这与表面具有较多的酸碱位数量和较大的孔体积有关。此外，采用密度泛函理论（DFT）的计算构建了单斜ZrO₂（111）和CeO₂（110）晶面，在单斜ZrO₂上加入Ce可以提高表面的酸性，进而改变其催化性能。

The catalytic performance of cerium-zirconium complex catalysts with Ce/Zr molar ratios of 1:19,1:9,2:8,and 3:7,prepared by hydrothermal method,are investigated for direct synthesis of dimethyl carbonate (DMC) from CO₂ and methanol in a high pressure stainless steel reactor remaining 3.5 MPa and at 160℃.These four kinds of catalysts are characterized by means of XRD,N₂ adsorption-desorption,FT-IR,NH₃-TPD,and CO₂-TPD.The results show that the addition of Ce does not change the crystalline phase of monocline ZrO₂.The catalyst with a Ce/Zr molar ratio of 2:8 (Ce_0.2ZrO₂) shows excellent catalytic performance,which is related to the larger amount of surface acid-base sites and the larger pore volume.In addition,ZrO₂(111) and CeO₂(110) are constructed by means of density functional theory (DFT) calculations.It is found that doping CeO₂ on monocline ZrO₂ can increase its surface acidity and thus change its catalytic properties.

王旭慧(1984-),女,博士研究生,讲师,研究方向为一碳化学与化工,1049500453@qq.com