Glycine photosynthesis via C−N coupling of waste plastic and nitrate over diatomic Pd−B catalyst
Zongyang Ya, Mei Li, Donglong Fu, Yu Zheng, Ruhan Wei, Hao Wang, Kangning Zhang, Dong Xu, Zixuan Zhang, X. Zhang, Shen Yan, Hua Wang, Shengbo Zhang, Jinlong Gong
Abstract
Photocatalytic C−N coupling offers a promising approach for the sustainable production of amino acids, but the uncontrolled coupling pathway of reaction intermediates limits yield and selectivity. This paper describes a Pd−B diatomic catalyst that can selectively catalyze the photosynthesis of glycine via C−N coupling reaction between waste poly(ethylene terephthalate)-derived ethylene glycol and nitrate, achieving a glycine yield of 2.9 mmol gcat−1 h−1 with a selectivity of 92%. Mechanistic investigations reveal that ethylene glycol is photo-oxidized to glycolaldehyde at the hole-rich B site, while nitrate is photo-reduced to NH4+/NH3 at the electron-rich Pd site. Subsequently, glycolaldehyde undergoes C−N coupling with NH4+/NH3, and further photo-oxidized to form glycine. The Pd−B diatomic site more effectively stabilizes the glycolaldehyde intermediate, resulting in a more favorable C−N coupling pathway than metal oxide and enhancing glycine selectivity. Thus, we show a catalytic system for selective glycine photosynthesis by precisely regulating the reaction pathways of key intermediates. This work describes a Pd−B diatomic catalyst that can selectively catalyze the photosynthesis of glycine via C−N coupling reaction between PET-derived ethylene glycol and nitrate, achieving a yield of 2.9 mmol gcat−1 h−1 and selectivity of 92%.