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 TiO 2 in the course of oxidative regeneration of ZnO−TiO 2 in the presence of O 2 and H 2 O was studied. ZnO−TiO 2 and ZnO were prepared by a precipitation method using aqueous solutions of Zn(NO 3 ) 2, Ti(SO 4 ) 2, TiO 2 sol, and NH 3 . The oxidative regeneration character of the spent ZnO−TiO 2 and ZnO was examined using a temperature-programmed reaction technique and isotopic H 2 18 O. It was found that TiO 2 accelerated both the reaction between ZnS and O 2 and the reaction between ZnS and H 2 O and also accelerated the oxidative regeneration of ZnS in the presence of both O 2 and H 2 O. Furthermore, the acceleration in the presence of both O 2 and H 2 O could be explained by an activation of H 2 O over TiO 2 and spillover of the activated H 2 O species.