Hydrodeoxygenation of lignin-derived oxygenated aromatic compounds catalyzed by nano-floral hydrotalcite for the preparation of liquid-phase organic hydrogen carriers

Abstract

Lignin-derived oxygenated aromatic compounds have the potential to serve as renewable feedstocks to cycloalkanes that can be used as liquid organic hydrogen carriers . In this work, different trimetallic hydrotalcite-based catalysts were prepared for the hydrodeoxygenation of lignin monomers into cycloalkanes. The results showed that the RuNiAlO x catalysts possessed unique flower-like pore structure , excellent surface properties, abundant active and acidic sites, strong adsorption capacity, and oxygen vacancies , which jointly determine the superb performance of RuNiAlO x catalysts in catalyzing a spectrum of lignin monomers into cycloalkanes. Using vanillin as the substrate, the conversion reached 100 % to afford cycloalkane in yield up to ∼99 % at 260 °C, 2 MPa H 2 and 3 h. The present study offers the possibility of an efficient conversion and utilization of lignin oil, which is expected to alleviate the challenges associated with hydrogen storage and transportation. • Hydrotalcite-based catalysts were prepared for vanillin hydrodeoxygenation to cycloalkanes. • Synergistic effect of Ru and Ni contributes to the enhancement of vanillin hydrodeoxygenation performance. • Adsorption sites of oxygen-containing functional groups are related to the acidity of the metal. • Vanillin can be efficiently converted to high yields of cycloalkanes.