Ammonia-Assisted Photosynthesis of Ethylene Glycol

Abstract

Photocatalytic C-C coupling of methanol provides an appealing approach to producing ethylene glycol (EG) with theoretically zero-carbon cost loss. However, the high polarity of the O-H group severely inhibited the formation and desorption of key radical intermediates, resulting in a low ethylene glycol yield and selectivity. Herein, we report an ammonia-assisted method to promote the efficient photosynthesis of ethylene glycol by amino/ammonia modification on the catalyst surface. After optimization, a 45-fold enhancement of the ethylene glycol production rate (5085 μmol g^-1 h^-1) and an outstanding rise of carbon selectivity can be obtained (91.1%). As revealed by a series of in situ characterizations, we demonstrate that the hydrogen bond between absorbed methanol and the amino group/ammonia could restrain the preferential oxidation of hydroxyl groups on the catalyst surface, leading to the productive production of key ·CH₂OH for high-efficiency ethylene glycol photosynthesis. This work demonstrated that nonchemical bonding interactions can effectively modulate radical reaction pathways, thereby enabling high-selectivity photocatalysis.