Promotional effects of magnesia on catalytic performance of Pt/SiO2 in hydrogenolysis of dibenzofuran

摘要

Developing mechanistic insights into the promotional effect of alkaline earth metal oxides in the hydrogenolysis of lignin-derived dibenzofuran (DBF) is key to rational design of high-performance catalysts for bio-oils upgrading. The promotional effect of MgO on Pt/SiO2 catalyst for the hydrogenolysis of DBF has been investigated. Small amounts of MgO enriches the electron density of Pt surface and the Lewis acidity of support, leading to significant improvement of the reactivity with an excellent turnover frequency (TOF) of 1182 h(-1) on Pt/3MgO/SiO2 compared with 789 h(-1) on Pt/SiO2. The high selectivity for biphenyl depends on the combination of the acid-base properties. With the same moles of alkaline earth dopants, the activity of dopants decreased in the order: Mg > Ca > Sr > Ba, resulting from the decrease in Pt dispersion, and, decreasing linearly with decreasing electronegativity. Additionally, in 240 h stability test, Pt/3MgO/SiO2 catalyst showed considerably stable activity and selectivity. (C) 2019 Elsevier Inc. All rights reserved.