Influence of periodic nitrogen functionality on the selective oxidation of alcohols.

An enhancement in catalytic alcohol oxidation activity is attributed to the presence of nitrogen heteroatoms on the external surface of a support material. The same Pd particles (3.1-3.2 nm) were supported on polymeric carbon-nitrogen supports and used as catalysts to selectively oxidize benzyl alcohol. The polymeric carbon-nitrogen materials include covalent triazine frameworks (CTF) and carbon nitride (C(3)N(4)) materials with nitrogen content varying from 9 to 58 atomic percent. With comparable metal exposure, estimated by X-ray photoelectron spectroscopy, the activity of these catalysts correlates with the concentration of nitrogen species on the surface. Because the catalysts showed comparable acidic/basic properties, this enhancement cannot be ascribed to the Lewis basicity but most probably to the nature of N-containing groups that govern the adsorption sites of the Pd nanoparticles.