In situ synthesis of Au/Ti-HMS and its catalytic performance in oxidation of bulky sulfur compounds using in situ generated H2O2 in the presence of H2/O2

Gold particles are supported on Ti-containing mesoporous silica (Ti-HMS) through an in situ process. The obtained samples were characterized by a series of techniques including ICP, powder X-ray diffraction, N2 sorption, UV-visible spectroscopy and transmission electron microscopy. The performance of the catalyst in direct synthesis of H2O2 from H2/O2 in methanol solvent and oxidative desulphurization using the in situ generated H2O2 have been systematically investigated. The results show that in situ synthesized Au/Ti-HMS, the organic template of which is eliminated via extraction with ethanol, successfully maintains the typical wormhole structure of HMS and possesses uniform mesopores, which is confirmed by N2 sorption and TEM. UV-visible spectroscopy result confirms the simultaneous existence of Au and Ti active centers in this bifunctional catalyst. Gold particles supported on Ti-HMS show high activity in the direct synthesis of H2O2 from H2 and O2 in methanol solvent. Furthermore, high removal rate of bulky sulfur compounds can be obtained using the in situ generated H2O2 over Au/Ti-HMS. Final conversion rate of the substrates confirms the dominant role of the in situ H2O2 oxidation in deep desulphurization. In addition, this bifunctional catalyst can avoid the insufficiency of H2O2 caused by the decomposition comparing with the Ti-HMS/commercial H2O2 system.