Bifunctional Ni catalysts for the one-pot conversion of Organosolv lignin into cycloalkanes

Abstract

In this report, Ni/ZrO2, Ni/Al2O3, Ni/Al2O3-KF, Ni/SBA-15, and Ni/Al-SBA-15 were examined as catalysts for the hydrodeoxygenation of diphenyl ether. Adopting the degree of deoxygenation and yield of monocyclic products as the criteria for the catalyst selection, Ni/Al-SBA-15 was identified as the best catalyst for HDO of diphenyl ether. In fact, in the presence of Ni/Al-SBA-15, full conversion of the model compound into cyclohexane was achieved with high selectivity (98%). Most strikingly, Ni/Al-SBA-15 is capable of hydrodeoxygenating Organosolv lignin with selectivity to cycloalkanes higher than 99%. Owing to the similarities to hydrocarbons derived from petroleum, the lignin-derived alkanes could well be refined into drop-in fuels by conventional oil refinery processes. Moreover, in a broader perspective, the current results also highlight the importance of Al-SBA-15, as an acidic support alternative to zeolites or other acidic materials, for the HDO of phenolic streams.