Vanadia nanoparticles encapsulated in mesoporous silica as a rattle-like structure for oxidation of dibenzothiophene: A kinetic study

A rattle-like structure of V2O5 encapsulated in mesoporous silica was successfully prepared through a surfactant-supported selective etching strategy. The structural analysis showed that V2O5 nanoparticles in the core of mesoporous hollow silica spheres with void diameter ∼290 nm, V2O5 core diameter ∼93 nm, amorphous SiO2 shell thickness ∼17 nm, surface area of ∼368.19 m2/g and average pore radius of 16 nm. The as-prepared material was employed in catalytic oxidation of dibenzothiophene (DBT) in the presence of H2O2 as an oxidizing agent at different conditions of temperature, contact time and initial concentration using a batch system under either stirring or ultrasonication. The ultrasonication was found to be more effective (∼100%) and faster in oxidation process than the stirring (∼68%, after 5 h). The analysis of the outputs significantly indicated the adsorption of the produced sulfone onto the catalyst surface. The catalytic system exhibited high removal efficiency, qe (∼493 mg/g), as detected experimentally at ambient condition. The thermodynamic analysis confirms the spontaneous physic-sorption nature of the adsorption process with adsorption energy ∼2.155 kJ/mol. The intra-particle diffusion model indicates that the process passes through three stages to attain the equilibrium state.