Li Xu, Shi Hua, Gu Yunhan, Cheng Qingyan, Wang Yanji
Key Laboratory of Green Chemical Technology and High Efficient Energy Saving of Hebei Province, Tianjin Key Laboratory of Chemical Process Safety, School of Chemical Engineering, Hebei University of Technology, Tianjin 300401, China.
China Tianchen Engineering Corporation, Tianjin 300499, China.
Molecules. 2022 Jan 2;27(1):270. doi: 10.3390/molecules27010270.
A citric acid ligand assisted self-assembly method is used for the synthesis of ternary mesoporous cerium lanthanum solid solution doped with metal elements (Co, Zr, Mg). Their textural property was characterized by X-ray diffraction, transmission electron microscopy, N adsorption-desorption, X-ray photoelectron spectroscopy and TPD techniques, and so on. The results of catalytic testing for synthesis of dimethyl carbonate (DMC) from CHOH and CO indicated that the DMC yield reached 316 mmol/g on Ce-La-Co solid solution when the reaction temperature was 413 K and the reaction pressure was 8.0 MPa. It was found that Co had synergistic effect with La and Ce, doping of Co on the mesoporous Ce-La solid solution was helpful to increase the surface area of the catalyst, promote CO adsorption and activation, and improve the redox performance of solid solution catalyst. The conversion of Co to Co resulted in the continuous redox cycle between Ce and Ce, and the oxygen vacancy content of the catalyst was increased. Studies have shown that the catalytic performance of Ce-La-Co solid solution is positively correlated with oxygen vacancy content. On this basis, the reaction mechanism of DMC synthesis from CO and CHOH on the catalyst was speculated.
采用柠檬酸配体辅助自组装法合成了掺杂金属元素（Co、Zr、Mg）的三元介孔铈镧固溶体。通过X射线衍射、透射电子显微镜、N2吸附-脱附、X射线光电子能谱和TPD技术等对其织构性质进行了表征。由CHOH和CO合成碳酸二甲酯（DMC）的催化测试结果表明，当反应温度为413K、反应压力为8.0MPa时，Ce-La-Co固溶体上DMC的产率达到316mmol/g。发现Co与La和Ce具有协同作用，在介孔Ce-La固溶体上掺杂Co有助于增加催化剂的比表面积，促进CO的吸附和活化，提高固溶体催化剂的氧化还原性能。Co向Co的转变导致Ce和Ce之间的连续氧化还原循环，催化剂的氧空位含量增加。研究表明，Ce-La-Co固溶体的催化性能与氧空位含量呈正相关。在此基础上，推测了CO和CHOH在该催化剂上合成DMC的反应机理。
