Functionalized Graphitic Carbon Nitride Decorated with Palladium: An Efficient Heterogeneous Catalyst for Hydrogenation Reactions Using KHCO₂as a Mild and Noncorrosive Source of Hydrogen

Functionalization of the widely known graphitic carbon nitride (GCN) material has been performed, and a novel heterogeneous catalyst is reported by incorporating palladium over the surface of functionalized GCN. GCN was functionalized using an optimized ratio of sulfuric acid, nitric acid, and hydrogen peroxide. The developed catalyst was characterized by powder X-ray diffraction, IR, scanning tunneling microscopy, tunneling electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller, thermogravimetric analysis, and solid-state CP-NMR. The developed material containing ≤1% Pd exhibits superior catalytic activity in comparison to other carbon support materials (such as 5% Pd/C) for various hydrogenation reactions under mild conditions. Potassium formate has been chosen as the best hydrogen source among other alkali metal formates. The developed catalyst was also able to catalyze a one-pot three-step reaction for the synthesis of N-benzylaniline which is a precursor of various antihistamine and anticholargenic drugs. Moreover, the catalyst could be recycled multiple times and consistent activity was reported.