Cao Xiaoyan, Kong Lingxin, Gu Zhenggui, Xu Xiao
School of Chemistry and Materials Science, Nanjing Normal Univesity Nanjing 210023 China
Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal Univesity Nanjing 210023 China.
RSC Adv. 2022 Aug 16;12(36):23183-23192. doi: 10.1039/d2ra03716e.
The application of recyclable heterogeneous catalysts in the production of polypropylene glycol monomethyl ether (MPPG) is of great significance to the green chemical industry. In this study, the CeO/MgAl-LDH(P123) composite was prepared using a nucleation/crystallization isolation method and aqueous reconstruction method, and CeO/MgAl-LDO(P123) solid base catalyst was prepared by calcination with it as precursor. Thereafter, the morphology, crystal structure, functional group, and thermal stability of the catalyst were characterized using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, temperature-programmed desorption of carbon dioxide, thermogravimetry, and X-ray photoelectron spectroscopy. The results showed that the catalyst had a larger specific surface area, pore size and pore volume and more basic sites, providing sufficient catalytic activity for the polymerization process. The experimental results for the fabrication of MPPG using CeO/MgAl-LDO(P123) as catalyst and methanol and propylene oxide as reaction raw materials showed that the conversion of propylene oxide reached 92.04% and the molecular weight of MPPG was 405 under the optimal reaction conditions. Moreover, the conversion of propylene oxide was maintained above 83.69% after the catalyst was reused six times. This study offers a new prospect for the green synthesis of MPPG products.
可回收多相催化剂在聚丙二醇单甲醚(MPPG)生产中的应用对绿色化学工业具有重要意义。本研究采用成核/结晶隔离法和水体重构法制备了CeO/MgAl-LDH(P123)复合材料,并以其为前驱体通过煅烧制备了CeO/MgAl-LDO(P123)固体碱催化剂。此后,利用扫描电子显微镜、X射线衍射、傅里叶变换红外光谱、BET分析、二氧化碳程序升温脱附、热重分析和X射线光电子能谱对催化剂的形貌、晶体结构、官能团和热稳定性进行了表征。结果表明,该催化剂具有较大的比表面积、孔径和孔容以及更多的碱性位点,为聚合过程提供了足够的催化活性。以CeO/MgAl-LDO(P123)为催化剂、甲醇和环氧丙烷为反应原料制备MPPG的实验结果表明,在最佳反应条件下,环氧丙烷的转化率达到92.04%,MPPG的分子量为405。此外,催化剂重复使用6次后,环氧丙烷的转化率保持在83.69%以上。本研究为MPPG产品的绿色合成提供了新的前景。