Selective hydrodeoxygenation of guaiacol to cyclohexanol over NixCoyAlz catalysts under mild conditions

Hydrodeoxygenation is one of the key steps to upgrade of biomass derived bio-oil into valuable biofuels and chemicals. Developing of highly reactive and cost-effective catalysts for bio-oil hydrodeoxygenation is highly desired. Layered NixCoyAlz catalyst was prepared using layered double hydroxide (LDH) as the precursors. The optimized Ni1Co3Al2-600 catalyst exhibits excellent catalytic performance for guaiacol hydrodeoxygenation. Guaiacol could completely converted with 90.0% of cyclohexanol selectivity under relatively mild reaction conditions. The XRD and HRTEM characterizations of the as prepared catalysts confirmed the formation of Ni-Co alloy and the XPS analysis revealed the strong interaction between Al species with both Ni and Co in catalyst Ni1Co3Al2-600, which should contribute to its high catalytic activity for guaiacol hydrodeoxygenation. Catalyst Ni1Co3Al2-600 also demonstrated excellent versatility for the hydrodeoxygenation reactions of guaiacyl and syringyl compounds as well as high stability. The results from this work could provide a new approach for the constructing of effective catalysts from non-noble metal LDHs.