Electronic-Enriched Ru on Boron Nitride Enabled Efficient Catalytic Transfer Hydrogenolysis of Lignin Models

Abstract

Catalytic transfer hydrogenolysis (CTH) of aromatic ether bonds provides a promising strategy for sustainably converting lignin into useful chemicals. Design of innovative catalysts with high activity is the key for this route. Herein, we constructed the hexagonal boron nitride (h-BN)-supported Ru nanoparticles (Ru/h-BN) as the heterogeneous catalyst for the CTH of aromatic ether bonds. Notably, the fabricated Ru/h-BN catalyst could efficiently catalyze CTH of various types of aromatic ether bonds contained in lignin (i.e., 4-O-5, α-O-4, β-O-4, and aryl-O-CH₃) employing 2-propanol as the hydrogen resource without using extra acidic or basic additives. Besides, the Ru/h-BN catalyst demonstrated superior performance compared to commercial Ru/C. Systematic investigation revealed that electron-enriched Ru sites and the B atoms on h-BN collaboratively promoted the CTH reaction. Besides, a mechanism study indicated that the direct cleavage of aromatic ether bonds was the primary reaction pathway over Ru/h-BN.