Hydrodeoxygenation of lignin-derived phenolic compounds over bi-functional Ru/H-Beta under mild conditions

Abstract

Bifunctional ruthenium catalysts supported on H-Beta zeolite were designed and applied in the hydrodeoxygenation of lignin-derived phenolic compounds for bio-oil upgrading. The oxygen-containing groups in lignin-derived phenolic monomers and dimers could be efficiently removed through aqueous phase hydrodeoxygenation catalyzed by Ru/H-Beta under very mild conditions, i.e. at 413 K and 4 MPa H2. Characterization results revealed that ruthenium species existed in the form of highly dispersed nanoparticles on H-Beta zeolite, while the presence of both Brønsted and Lewis acid sites in zeolite was crucial for the remarkable hydrodeoxygenation activity. The effects of reaction conditions and catalyst constitution on the catalytic performance of Ru/H-Beta in hydrodeoxygenation were systematically investigated. The hydrodeoxygenation pathway of diphenyl ether as a model compound catalyzed by optimized 0.5%Ru/H-Beta was discussed and the structure-activity relationship in hydrodeoxygenation was proposed.