Photocatalytic synthesis of ethylene glycol and hydrogen from methyl tert-butyl ether.

In this work, we have developed a green and sustainable strategy for the synthesis of ethylene glycol, which is a highly valuable compound in chemical industry. In contrast to the currently applied energy-intensive process based on petroleum resources, this work demonstrates the photocatalytic pathway of methanol dehydrogenative coupling to produce ethylene glycol, utilizing methyl tert-butyl ether as the substrate to protect the hydroxyl group against oxidation. Photocatalytic tests reveal efficient C-C coupling of methyl tert-butyl ether with Pt/C-TiO(B)-650 catalyst under light irradiation, with the target product 1,2-di-tert-butoxyethane at a selectivity of 67% and a Pt-based turnover frequency of 2754 h-1. Scale up test demonstrates high stability of the system, reaching an accumulated turnover number of 120 000 as well as isolation of 13 g of the coupling product after 130 h irradiation. The target ethylene glycol is obtained by the hydrolysis of the dimer using the regenerable acidic resin catalyst.