Selective Upgrading of Biomass-Derived Carbonyl Compounds by Nickel-Base Catalyst in Isopropanol

Low-cost nickel catalyst (Ni@C/C) derived from a metal organic framework (MOF) was synthetized for the hydrodeoxygenation (HDO) of biomass-derived vanillin. Unlike expensive noble-metal catalysts, Ni@C/C achieves full conversion of vanillin to 2-methoxy-4-methylphenol (MMP)—a key biofuel precursor—under mild conditions (180 °C, 2 MPa H₂). Ni@C/C exhibited excellent catalytic activity for the HDO of vanillin in isopropanol. Moreover, the main product of vanillyl alcohol (VA) under N 2 was 4-(isopropoxymethyl)-2-methoxyphenol (iPMP). The possible mechanism of vanillin by using Ni@C/C catalyst was that Vanillin was hydrogenated to generate VA, and VA was hydrogenated on Ni@C/C to generate MMP by two HDO paths: (1) VA was directly HDO to generate MMP; (2) VA was hydrogenated with isopropanol to generate iPMP by dehydration, then iPMP was hydrogenated to produce MMP. The Ni-based catalyst is relatively cheap and the preparation method is facile, green, and easy to scale up, thus achieving a low-cost transformation of biomass to bio-oils and chemicals. Graphical