Mesoporous Ni/Al-MCM-41 catalysts for highly active and selective hydrodeoxygenation of anisole to cyclohexane

Ni/Al-MCM-41(x) catalysts were synthesized and tested in the hydrodeoxygenation of anisole as a model compound of bio-oil. Prepared catalysts behave as bifunctional metal-acid catalysts combining the metal function of the reduced Ni nanoparticles with the acid function of the Al-MCM-41 supports. Nickel loading in the catalysts was maintained constant (5 wt%), while Al content in the supports was varied (Si/Al molar ratios x = 120, 90, 60 and 30). The Ni/Al-MCM-41(x) catalysts showed significantly higher hydrodeoxygenation activities than the reference Ni/Al2O3 and the Ni/MCM-41 catalyst without Al. In addition, they showed high selectivity towards the formation of the deoxygenated products, with more than 96% selectivity to cyclohexane. The best activity and selectivity results were obtained with the Ni/Al-MCM-41(90) catalyst. This result was attributed to an optimum balance of metal and acid sites, both of which participate in different steps of anisole hydrodeoxygenation and generate a synergistic effect.