Tuning of surface structure of porous glass-supported titania with fibrous silica for efficient coupling adsorption‒catalysis‒resorption desulfurization scheme

Abstract

A core-shell porous catalyst of porous glass coated with TiO2-fibrous silica (KCC-1) was prepared. The fibrous structure of KCC-1 can load a large quantity of titanium dioxide with minimum loss of surface area. Effects of the reaction time, quantity of TiO2 coated, initial concentration of sulfide, and reaction temperature on the desulfurization rate were investigated, and the prepared catalysts showed excellent catalytic desulfurization performance. The desulfurization rate of the composite catalyst with 35 wt% TiO2 coating in simulated fuel with 50 mg/L DBT concentration can reach 94.91% at 293.15 K within 160 min. Compared with other studies, the unit desulfurization rate is improved significantly without introducing any additional oxidants. In addition, in order to verify the effectiveness of the adsorption‒catalysis‒resorption desulfurization system, the adsorption kinetics and thermodynamics were studied, and the surface binding energy between the catalyst and the sulfide was calculated using Material Studio software. Experiments and simulations revealed that good adsorption performance of the catalyst on the reactants will greatly enhance the heterogeneous reaction rate for the enrichment of reactants on the surface of the catalyst, and the products can be selectively adsorbed on the catalyst surface via strong polar interaction to achieve coupling desulfurization of adsorption-catalysis-resorption in the initial position. In addition, spent TiO2-KCC-1/PG can be regenerated by simple thermal treatment and no visible decrease will be observed in the desulfurization rate after three regeneration cycles.