TiO2-x modified Ni/SBA-15 catalysts for dibenzofuran hydrodeoxygenation

The presence of oxygenated compounds in coal-based crude oil seriously affects its calorific value. Dibenzofuran, as a compound with a certain content in coal-based crude oil and difficult to hydrodeoxygenate, is often chosen as a model compound. The influence of decorating the surface of a Ni catalyst with TiO2 on the activity and selectivity for dibenzofuran hydrodeoxygenation was investigated in this study. Ring opening and dehydroxylation of six oxygen-containing intermediates on the Ni(111) surface and the interfacial sites between Ni(111) and TiO2 were compared by density functional theory calculations. Results showed that the activation of C−O bonds was promoted by the enhanced adsorption of oxygen-containing intermediates at the interfacial sites. The decoration of TiO2 on Ni metal can obviously promote the conversion of dibenzofuran and selectivity of deoxygenation products. The yield of the target product of bicyclohexane was the highest and reached up to 94.8% when the mole ratio of Ni/Ti was 1:3. The addition of TiO2 not only promoted the dispersion of Ni particles but also enhanced the reduction of Ni2+ to Ni0. However, there were no significant electronic modifications were detected for the bulk of the metallic Ni particles and changed the acidity of the catalyst. It is concluded that the improved deoxygenation performance of the catalyst was due to the interfacial sites created by TiO2 decorating on the surface of Ni particles. It can provide a valuable reference for catalysts design of fuel conversion technology and environmental science.