硫酸盐化对TiO_2催化剂克劳斯活性的影响

Influence of sulfation on Claus activity of TiO_2 catalyst

采用硫酸铵浸渍的方法制得了一系列硫酸盐化的催化剂,运用TG、BET比表面测定、XRD、Raman、FTIR和SO2-TPD技术对催化剂进行了表征,并对催化剂进行了克劳斯活性评价。结果表明,硫酸盐化会导致催化剂比表面积和孔体积减小但不会使催化剂形成新的晶型,硫酸盐的形成使TiO2表面碱性变弱,硫酸根在TiO2表面形成的双齿螯合结构会阻碍SO2和H2S与催化剂表面的接触,碱性变弱和双齿螯合结构的形成导致了催化剂克劳斯活性降低,另外,负载的硫酸盐的量越多催化剂的克劳斯活性越低。

To study the effect of sulfation on the Claus activity of the TiO2 catalyst,the catalysts were impregnated with solutions of ammonium sulfate as precursor. The structure of the catalyst was characterized by TG,XRD,Raman,FT-IR and SO2-TPD and the Claus activity was tested. The results showed that with the sulfate increasing,the surface area and total pore volume decreased but the new phase was not formed. The introduction of sulfate reduced the base properties of the catalyst. The structure combined SO2-4with metal ions of TiO2 in a chelating bidentate hindered the contact of SO2 or H2S with the surface active sites. Accordingly,the Claus activity of the catalyst decreased. In addition,the more sulfates content will have the lower activity of the Claus catalyst.