Insights into kinetics and reaction mechanism of acid-catalyzed transesterification synthesis of diethyl oxalate

• Published in: Resources Chemicals and Materials Vol. 3; no. 1; pp. 93 - 101
• Main Authors: Zhang, Naiwen, Xia, Rui, Wan, Siyu, Xiong, Xinyang, Zhao, Jinggang, Zhou, Jun, Shi, Lei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2024; KeAi Communications Co., Ltd
• Subjects: Acidic catalyst; Diethyl oxalate; Kinetics; Reaction mechanism; Transesterification; Reaction mechanism; Acidic catalyst; Diethyl oxalate; Transesterification; Kinetics
• ISSN: 2772-4433; 2772-4433
• DOI: 10.1016/j.recm.2023.08.003

•Bronsted acids tended to protonate the carbonyl oxygen to form the important carbocation intermediate.•The FeCl3-catalyzed transesterification reaction has a lower energy barrier than that of H2SO4.•The stronger electron-absorbing effect of C = O adjacent group contributed an easy nucleophilic addition. The catalytic performance of different acidic catalysts for diethyl oxalate synthesis from the one-step transesterification of dimethyl oxalate and ethanol was evaluated. The effects of different factors (e.g., acidity, electron accepting capacity, cations type and crystalline water) on the catalytic activity of acidic catalysts were investigated respectively. It was proposed and confirmed that the transesterification reaction catalyzed by a Lewis acid (FeCl3) and a Bronsted acid (H2SO4) follows a first-order kinetic reaction process. In addition, the Lewis acid-catalyzed transesterification processes with different ester structures were used to further explore and understand the speculated reaction mechanism. This work enriches the theoretical understanding of acid-catalyzed transesterification reactions and is of great significance for the development of highly active catalysts for diethyl oxalate synthesis, diminishing the industrial production cost of diethyl oxalate, and developing downstream bulk or high-value-added industrial products. [Display omitted]