Boosting Selective Oxidation of Ethylene to Ethylene Glycol Assisted by In situ Generated H2O2 from O2 Electroreduction

Ethylene glycol is a useful organic compound and chemical intermediate for manufacturing various commodity chemicals of industrial importance. Nevertheless, the production of ethylene glycol in a green and safe manner is still a long-standing challenge. Here, we established an integrated, efficient pathway for oxidizing ethylene into ethylene glycol. Mesoporous carbon catalyst produces H2O2, and titanium silicalite-1 catalyst would subsequently oxidize ethylene into ethylene glycol with the in situ generated H2O2. This tandem route presents a remarkable activity, i.e., 86 % H2O2 conversion with 99 % ethylene glycol selectivity and 51.48 mmol g(ecat)(-1) h(-1) production rate at 0.4 V vs. reversible hydrogen electrode. Apart from generated H2O2 as an oxidant, there exists (OOH)-O-center dot intermediate which could omit the step of absorbing and dissociating H2O2 over titanium silicalite-1, showing faster reaction kinetics compared to the ex situ one. This work not only provides a new idea for yielding ethylene glycol but also demonstrates the superior of in situ generated H2O2 in tandem route.

Automated summary

We have established an integrated pathway for oxidizing ethylene into ethylene glycol using mesoporous carbon catalyst and titanium silicalite-1 catalyst. This pathway exhibits remarkable activity, achieving 86% H2O2 conversion, 99% ethylene glycol selectivity, and a production rate of 51.48 mmol g(ecat)(-1) h(-1) at 0.4 V vs. reversible hydrogen electrode. In addition to using generated H2O2 as an oxidant, there is also an (OOH)-O-center dot intermediate that eliminates the step of absorbing and dissociating H2O2, showing faster reaction kinetics compared to the ex situ approach. This work not only provides a new idea for ethylene glycol synthesis but also demonstrates the advantage of in situ generated H2O2 in the tandem route.