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

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.