The Preparation and Characterization of Solid Superacid S2O82-/SnO2-SiO2
The new type of solid superacid S2O82-/SnO2-SiO2 was prepared by precipitation and hydrothermal aging method with ammonium persufate as soaker instead of sulphuric acid. The samples with different tin oxide content were characterized by FT-IR, XRD, BET, TG/DTA and Hammett indicators techniques. Catalytic activities for esterification of butanol and acetic acid were also investigated. As a result, most sulfate-ion in surface of S2O82-/SnO2-SiO2 coordinate with Sn bidentatly, and the acidic strength of S2O82-/SnO2-SiO2 is related to the content of tin oxide. Besides, introducing appropriate Si can improve the combination of the tin with SO42- thus increases the amount of acid. Catalyst S2O82-/SnO2-SiO2 reveals high catalytic activity and stability in the esterification at very large range of composition.
Yun-Hae Kim, Prasad Yarlagadda, Xiaodong Zhang and Zhijiu Ai
X. Y. Hao et al., "The Preparation and Characterization of Solid Superacid S2O82-/SnO2-SiO2", Advanced Materials Research, Vols. 335-336, pp. 212-217, 2011