Synergistic effects of highly active Ni and acid site on the hydrodeoxygenation of syringol

The hydrodeoxygenation of syringol was explored with novel step by step precipitated Ni/SiO2-Al2O3 catalyst under mild conditions. Demethoxylation and dehydroxylation occurred in the first step, followed by the hydrogenation of benzene. Cyclohexane was formed eventually. Ni/SiO2-Al2O3 catalyst possessed high nickel dispersion and high amounts of acid sites. The synergistic effects of highly active Ni and acid site were the key to realize the occurrence of deoxygenation. These specialties resulted in the complete conversion of syringol at 200 °C, with the cyclohexane selectivity up to 97.8%, much better than the hydrodeoxygenation performances of single Ni/SiO2 and Ni/Al2O3.