Role of TiO2 on oxidative regeneration of spent high-temperature desulfurization sorbent ZnO-TiO2

To develop an easily regenerable high-temperature desulfurization sorbent, the role of TiO2 in the course of oxidative regeneration of ZnO-TiO2 in the presence of O-2 and H2O was studied. ZnO-TiO2 and ZnO were prepared by a precipitation method using aqueous solutions of Zn-(NO3)(2) Ti(SO4)(2), TiO2 sol, and NH3. The oxidative regeneration character of the spent ZnO-TiO2 and ZnO was examined using a temperature-programmed reaction technique and isotopic (H2O)-O-18. It was found that TiO2 accelerated both the reaction between ZnS and O-2 and the reaction between ZnS and H2O and also accelerated the oxidative regeneration of ZnS in the presence of both O-2 and E H2O. Furthermore, the acceleration in the presence of both O-2 and H2O could be explained by an activation of H2O over TiO2 and spillover of the activated H2O species.