Tuning support acidity of Ni-based catalysts to improve hydrodeoxygenation activity for dibenzofuran

Controlling the oxygen-free product selectivity in catalytic hydrodeoxygenation is essential for producing high-quality fuel from coal- and biomass-derived liquids. In this paper, the selectivity of oxygen-free products and efficiency of hydrodeoxygenation of dibenzofuran as a model compound of coal- and biomass-derived liquids have been controlled by varying the Si content in the prepared catalysts (Ni/ x Si-OMA, where x  = SiO 2 /(SiO 2  + Al 2 O 3 ) and OMA  = ordered mesoporous alumina). In comparison, the hydrodeoxygenation of dibenzofuran was performed using Ni/SBA-15, which displayed the lowest selectivity of oxygen-free products at 36.4%. On the other hand, doping Si in OMA introduces the Brønsted acid sites, which desirably enhances the selectivity of oxygen-free products. Above 99% selectivity of oxygen-free products has been attained for Ni/30Si-OMA and Ni/40Si-OMA catalysts. The Lewis acid sites of the OMA promote the deoxygenation efficiency through the enhanced adsorption of oxygen-containing intermediates. Besides, the Brønsted acid sites generated in OMA as the result of Si-doping promote the ring-opening and dehydration reactions of the oxygen-containing intermediates, which further lead to an overall enhanced hydrodeoxygenation performance for dibenzofuran.