Synergy of in situ generated Cu0 and Lewis acid sites for efficient and selective hydrodeoxygenation of vanillin to 4-methylguaiacol

Hydrodeoxygenation represents a promising route for upgrading lignin-derived bio-oil into value-added fine chemicals, but it is challenging to obtain high yield and selectivity due to the varying dissociation energy of different oxygen-containing functional groups. Here, we strategically engineered a robust Cu-based catalyst for catalyzing vanillin to 4-methylguaiacol in a H-donor solvent under an inert N2 atmosphere, achieving simultaneously >99.9 % conversion and near-theoretical selectivity (99.6 %), as well as excellent cycling durability. First-principles calculations and control catalytic experiments confirmed the enhanced performance originated from (i) the downshifted d-band center of in situ generated Cu0 species induced by Al Lewis acid sites and (ii) the synergistic interplay between these Cu0 centers and adjacent Al Lewis acid sites, facilitated by isopropanol-mediated hydrogen transfer. This study demonstrates the feasibility of rationally designing high-performance catalysts featuring synergistic non-noble metals with Lewis acid sites, enabling efficient and selective upgrade of renewable peroxidized compounds into value-added products with enhanced cost-effectiveness and process safety.