Photocatalytic integrated production of hydrogen and imines from aromatic amines via Ni-mesoporous carbon nitride: An acceptorless dehydrogenative pathway

Abstract

Photocatalysis manifests an invariably quite sustainable process for various chemical transformations. Utilization of electrons and holes for H2 production and organic transformation boost up the chemical economics for the simultaneous production of H2 and value-added organic chemicals. This work demonstrated a photocatalytic acceptorless dehydrogenation (PAD) of aromatic amines to imines coupled with H2 evolution over mesoporous carbon nitride (SGCN) photocatalyst by using non-noble metal (Ni). As synthesized 2 wt% Ni@SGCN catalyst showed superior photocatalytic activity (visible light) for furfuryl amine valorization with H2 generation rate of 5.03 μmol/h/g along with 12.5% conversion to imine in 6 h. Among all, 4-methoxybenzylamine depicted a high H2 production rate of 23.58 μmol/h/g along with a maximum 36% conversion in 6 h. Eventually, an experiment under natural sunlight showed an H2 generation rate of 4.6 μmol/h/g along with 12% conversion of furfuryl amine in 6 h. Moreover, the AQE (%) of the H2 production was estimated to be 1.1% (400 nm, 20 mg catalyst).