文献类型：期刊文献

英文题名：A Combined Computational and Experimental Study on the Tetrabutylammonium Bromide Supported Organometallic/Triethylboron Catalytic System for the Copolymerization of CO2 and Propylene Oxide

作者：Haq, Ijaz Ul[1]; Ali, Nawab[2]; Wu, Xiaojiong[3]; Ding, Delong[3]; Ge, Chunliang[3]; Shen, Weihua[1]; Yang, Yi[3]; Fang, Yunjin[1]

机构：[1] State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai, China; [2] Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, China; [3] Zhejiang Zheneng Technology & Environment Group Co., Ltd., China

年份：2025

外文期刊名：SSRN

收录：EI(收录号：20250370527)

语种：英文

外文关键词：Byproducts - Carbonation - Catalysts - Chemical activation - Copolymerization - Design for testability - Molecular oxygen - Polypropylene oxides

摘要：The ring-opening copolymerization (ROCOP) of CO2 and propylene oxide (PO) is a promising route to sustainable polypropylene carbonate. However, rational catalyst design is hindered by a lack of mechanistic understanding. This study integrates computational and experimental approaches to elucidate the mechanism and demonstrate the efficacy of a catalytic system comprising triethylboron (Et3B), alkali metal tert-butoxide (MOtBu), and tetrabutylammonium bromide (TBAB). The superior performance of the MOtBu/TBAB/Et3B catalytic system is conclusively demonstrated to stem from a synergistic mechanism, as definitively revealed by DFT calculations. This mechanism is characterized by two critical, concurrent steps: (1) the dual activation of CO2, wherein the CO2 molecule is polarized and rendered nucleophilic through coordination of its oxygen atom by the M? cation and simultaneous engagement of its carbon center by the tert-butoxide nucleophile; and (2) the Lewis acid activation of PO, wherein the epoxide’s ring strain and electrophilicity are enhanced upon coordination by Et3B. This synergistic polarization of both monomers drastically lowers the kinetic barrier for the ring-opening and CO2 insertion steps. Experimentally, the pre-mixed MOtBu/TBAB/Et3B system significantly increased CO2 solubility in the reaction medium, boosting copolymerization efficiency. The KOtBu-based system outperformed its NaOtBu counterpart, demonstrating superior activity, selectivity towards copolymer versus cyclic carbonate byproducts, higher number-average molecular weight (Mn), and narrower dispersity (?). This combined computational and experimental work provides fundamental mechanistic insights and validates a highly active catalyst system for the sustainable synthesis of polypropylene carbonate. ? 2025, The Authors. All rights reserved.