Efficient Catalytic Hydrodeoxygenation of Aromatic Carbonyls over a Nitrogen-Doped Hierarchical Porous Carbon Supported Nickel Catalyst

Hydrodeoxgenation of ketones or aldehydes allows for efficient transformation of oxygen containing raw materials into value-added chemicals and biofuels, which calls for efficient but inexpensive alternative catalytic systems. In the present contribution, a nitrogen-doped hierarchical porous carbon (NHPC) was fabricated in a leavening method, functioning as a superior support for the anchoring of highly dispersed Ni nanoparticles (Ni/NHPC with similar to 6.5 nm Ni nanoparticles). When tested in hydrodeoxygenation of bio-derived vanillin (4-hydroxy-3-methoxybenzaldehyde), this catalyst demonstrated much enhanced catalytic activity as compared to Ni/HPC (HPC means hierarchical porous carbon without nitrogen doping). A direct hydrogenolysis or hydrogenation-hydrogenolysis reaction mechanism was proposed, which allows the present Ni/NHPC to exert full oxygen removal of a broad set of aromatic substrates with carbonyl or -OH at benzylic position. The modified electronic state of nickel interacted with nitrogen dopant and enhanced mass transfer contributed by the hierarchical porous structure of NHPC may be reasons for high reactivity.