Study of Dispersion and Thermal Stability of V2O5/TiO2−SiO2 Catalysts by XPS and Other Techniques
Study of Dispersion and Thermal Stability of V2O5/TiO2−SiO2 Catalysts by XPS and Other Techniques
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DOI：
10.1021/jp963091o
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发表时间：
1997-03
影响因子：
3.3
通讯作者：
B. M. Reddy;I. Ganesh;E. P. Reddy
中科院分区：
文献类型：
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作者：
B. M. Reddy;I. Ganesh;E. P. Reddy
采用均相沉淀法制备了高比表面积的二氧化钛-−-二氧化硅二元氧化物载体，并在载体表面包覆了一层氧化钒。在773~1073K温度范围内对载体和V2O5/−催化剂进行了热处理，并用X射线衍射仪、红外光谱、X射线光电子能谱、吸氧和比表面积等方法研究了热处理对催化剂分散性和热稳定性的影响。结果表明，即使在1073K以下的焙烧温度下，TiO2SiO2光催化剂仍具有较好的热稳定性。−-SiO_2的热稳定性较好。而V_2O_5/TiO_2-−-SiO_2催化剂的分散度和比表面积都很稳定，只有在873K焙烧温度下才稳定，超过此温度的热处理使钒和二氧化钛转变为晶相，然后由锐钛矿型转变为金红石型。
A high surface area titania−silica binary oxide support was prepared according to the homogeneous precipitation method and was coated with a monolayer of vanadium oxide. The TiO2−SiO2 support and the V2O5/TiO2−SiO2 catalyst were then subjected to thermal treatments from 773 to 1073 K. The influence of heat treatments on the dispersion and thermal stability was investigated by X-ray diffraction, FT infrared, X-ray photoelectron spectroscopy, oxygen uptake, and BET surface area methods. The results suggest that TiO2−SiO2 is quite thermally stable even up to 1073 K calcination temperature. However, the V2O5/TiO2−SiO2 catalyst is stable, in terms of dispersion and surface area, only up to a calcination temperature of 873 K. Thermal treatments beyond this temperature transformed vanadia and titania into crystalline phases and then titania anatase into rutile phase.