Green and continuous flow oxidation of ethylene sulfite to ethylene sulfate over highly selective titanium silicalite-1 catalyst

Ethylene sulfate (DTD) is a new type of solid electrolyte interphase (SEI) film-forming additive for lithium-ion batteries. DTD was typically synthesized in the industry by oxidation of ethylene sulfite (ES) with NaClO via a RuCl 3 -catalyzed reaction. However, this route generates significant amount of Cl-containing wastes, and the recovery of RuCl 3 is costly and technically challenging. Herein, we present a green and heterogeneous route for synthesizing DTD from ES, utilizing the Titanium Silicalite-1 (TS-1) and H 2 O 2 as catalysts and green oxidants, respectively. Our research reveals that the tetra-coordination framework of Ti in TS-1 serves as the main active site for the oxidation of ES, achieving a remarkable yield of DTD up to 92 % under optimized reaction conditions. Additionally, we developed a continuous green oxidation process for synthesizing DTD from ES, which is the first of its kind and has been successfully operated continuously for over 300 h. This work provides a cost-effective, green, and efficient route for synthesizing DTD from ES.