Highly Active and Stable Pt Catalyst Based on Coal Gasification Slag for Liquid Organic Hydrogen Carrier Dehydrogenation

Coal gasification slag (CGS) was used for modification and loaded platinum (Pt) to liquid organic hydrogen carrier (LOHC) for the first time. The carbon hybrid silica (C@SiO2) was prepared by removing metal oxides and carbon residue of CGS through acid treatment and calcination. The C@SiO2 loaded Pt (Pt-C@SiO2) exhibited only a 1.3% decrease in dehydrogenation conversion rate after 30 hours of continuous catalytic dehydrogenation of methylcyclohexane (MCH), and even after 100 hours, the decrease was only 4.9%. When Pt was directly loaded on CGS (Pt-CGS), it showed higher catalytic activity (dehydrogenation conversion rate was 20.4%), but lower catalytic stability (dehydrogenation conversion rate decreased by 56% after 7 hours). Additionally, commercial Pt-SiO2 catalysts exhibited poor dehydrogenation conversion rate, significantly lower than that of Pt-C@SiO2. Density functional theory calculations confirmed the influence of carbon hybrid SiO2 on the adsorption energy, electron transfer and density of states for the catalytic dehydrogenation of MCH. The highly active and stable Pt-C@SiO2 catalyst can be effectively utilized for LOCH while achieving high-value utilization of CGS solid waste.