二氧化钛基固体超强酸的结构及其光催化氧化性能

采用溶胶－凝胶法制备了多孔性，大比表面积的ＳＯ４＾２－／ＴｉＯ２固体超强催化剂，运用ＸＲＤ，ＢＥＴ比表面积测定，ＸＰＳ和ＵＶ－Ｖｉｓ反射光谱等技术对该催化剂的结构，表面状态以及半导体特征进行了表征，并通过ＣＨ３Ｂｒ，Ｃ６Ｈ６和Ｃ２Ｈ４等典型有机物的气相光催化氧化反应。

STRUCTURE OF TITANIA-BASED SOLID SUPERACIDS AND THEIR PROPERTIES FOR PHOTOCATALYTIC OXIDATION

Porous SO 2- 4/TiO 2 solid superacid catalysts with high specific surface area were prepared by sol gel method and characterized by X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS), N 2 sorption analysis applying BET method, and UV Vis reflectance spectroscopy. Photocatalytic oxidation of CH 3Br, C 6H 6 and C 2H 4 in air stream was studied over pure and sulfated TiO 2 catalysts, respectively. The results showed that the photocatalytic and structural properties of TiO 2 were greatly improved by sulfation. The sulfated TiO 2 (SO 2- 4/TiO 2) exhibited excellent reaction activity for photocatalytic decomposition of the organic compounds. When compared to unmodified TiO 2, the sulfated TiO 2 exhibited higher resistance to crystal phase transformation from anatase to rutile, higher resistance to crystal grain growth, higher specific surface area. As a result of sulfation, the band gap of SO 2- 4/TiO 2 increased and the band edge blue shifted to yield larger redox potential, leading to the increased photocatalytic efficiency.