SO2-4/ZrO2-SiO2超强酸催化剂研究(Ⅲ)(英文)——酸性及比表面积

系统地研究了SO2-4/ZrO2-SiO2催化剂的酸性和比表面积,采用吸附吡啶的红外光谱法、BET法以及指示剂法考察了催化剂的组成、温度以及其他处理条件对催化剂酸强度以及催化剂比表面积的影响.实验结果表明:在硅锆比小于10时,SO2-4/ZrO2-SiO2催化剂的比表面积随催化剂中硅锆比的增高而增大;在硅锆比为10左右时,比表面积可高达440m2/g,数倍于SO2-4/ZrO2催化剂的比表面积.在相同处理条件下,SO2-4/ZrO2-SiO2催化剂的酸强度低于SO2-4/ZrO2的酸强度.吸附吡啶的红外光谱证明该催化剂的表面酸点多为Lewis酸点.

A Study on the Superacid Catalyst SO2-4/ZrO2-SiO2 (Ⅲ):Acidity and Surface Areas

The acidity and surface area of catalyst SO2-4/ZrO2-SiO2 were invest igated in this paper，and the effects of composition and calcining temperature on the acidity and surface area were studied by IR of pyridine adsorbed on catalyst, the indicator method as well as the BET method. It was found that the surfac e area of SO2-4/ZrO2SiO2 catalyst increases with the increasing o f th e ratio of Si to Zr when the ratio is below 10. At the ratio of Si to Zr as 10, the surface area of the catalyst could go up to 440 m2/g. Under the same treat ment conditions, the SO2-4/ZrO2-SiO2 catalyst showed lower acid stre ngth than SO2-4/ZrO2 catalyst, but a greater amount of acid. The IR sp ectra of adsorbed pyridine showed that most of the acid sites on the surface of the catalyst are Lewis acid sites.