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考察了焙烧温度、活化温度等因素对S2 O2 -8/ZrO2 (PSZ)固体超强酸常温下催化正戊烷反应性能的影响 ,利用色谱 质谱 (GC MS)、傅里叶红外 (FT IR)、原位X 射线粉末衍射 (XRD)、比表面测定 (BET)、含硫量分析等手段研究了正戊烷反应产物、催化剂晶型变化及表面酸位类型等 .结果表明 ,焙烧温度和活化温度是影响催化反应活性的关键 .焙烧温度在 72 3～ 973K制备的PSZ固体超强酸催化剂 ,30 8K下对正戊烷均具有催化反应活性 ,82 3K焙烧样品活性最佳 ;对于最佳焙烧温度样品 ,活化温度在 373 6 73K之间 ,均具有较高的反应活性 ,活化温度为 5 2 3K时活性最佳 .异构化表观活化能为 4 1.7kJ/mol.整个反应大致可以分为 3个阶段 :反应初期 ,产物均为异戊烷 ,表明发生的是异构化反应 ;反应中期 ,异构化反应速率减低 ,产物中出现异丁烷 ,表明异构化反应和裂解反应同时发生 ;反应后期 ,异构化产物明显减少 ,异丁烷和己烷异构体明显增加 ,表明裂解反应已经取代异构化反应 ,成为反应的主流 .适宜的焙烧温度使ZrO2 晶化是形成超强酸的必要条件 ;合适的活化温度影响酸位类型 ,5 2 3K下活化的样品主要为强Br nsted酸位 ,同时有少量的强Lewis酸位存在 .
The effects of calcination temperature, activation temperature and other factors on the catalytic performance of n-pentane at ambient temperature of S2 O2-8 / ZrO2 (PSZ) solid superacid were investigated. The effects of calcination temperature and activation temperature on the catalytic performance of n-pentane were investigated by GC / MS, FT- In situ X-ray powder diffraction (XRD), specific surface area (BET) and sulfur content analysis were used to study the n-pentane reaction products, the change of the catalyst crystal form and the surface acid sites, etc. The results showed that the calcination temperature and activation temperature Is the key to affect the catalytic activity.The baking temperature 723 ~ 973K prepared PSZ solid superacid catalyst, 30 8K under n-pentane catalytic activity, 82 3K roasting samples best activity; for the best roasting temperature sample , The activation temperature between 373 6 73K, all have high reactivity, the activation temperature is 523K best activity isomerization apparent activation energy of 4 1.7kJ / mol. The whole reaction can be divided into 3 In the initial stage of the reaction, all the products were isopentane, indicating that the isomerization occurred. In the middle of the reaction, the isomerization reaction rate was reduced and isobutane was present in the product, indicating that the isomerization reaction and the cleavage reaction occurred at the same time. After the reaction, The product of isostructural reduction and the isobutane and hexane isomers increase obviously, which indicates that the cleavage reaction has replaced the isomerization reaction and becomes the mainstream of the reaction.The suitable calcination temperature makes the crystallization of ZrO2 necessary for the formation of superacid. Suitable The activation temperature affected the type of acid sites. The samples activated at 52K mainly showed strong Br nsted acid sites with a few strong Lewis acid sites present.