摘要
利用ＸＲＤ、ＤＴＡ、ＩＲ考察了预焙烧对铝交联蒙脱土（Ａｌ－ＣＬＭ）结构的稳定化作用及引入铂对稳定Ａｌ－ＣＬＭ结构的协同效应；用加压连续流动微反装置研究了Ｐｔ／Ａｌ－ＣＬＭ的ｎ－Ｃ_８芳构化性能与其结构稳定性的关系。结果表明：经４００－５００℃的高温预焙烧可使Ａｌ－ＣＬＭ在浸铂过程中保持较高的层结构有序度和规整性，相应保持较大的层间域尺度，对Ａｌ－ＣＬＭ的结构具有稳定作用；引入的铂与Ａｌ－ＣＬＭ的四面体片发生相互作用，可抑制硅氧四面体的扭曲旋转，从而阻抑八面体结构羟基的脱除，具有稳定结构羟基的作用；而Ｐｔ／Ａｌ－ＣＬＭ的ｎ－Ｃ_８芳构化Ｃ_８芳烃收率与其结构的完整性、有线性、相关性。
XRD,DTA and IR methods were used to investigate the effect of pre-calcination on stabilizing the structure of platinum containing Al cross-linking montmorillonite(Pt/Al-CLM). The promotion effect of platinum on stabilizing the Al-CLM structure was also probed with these methods. The relationship between the structure stability of Pt/Al-CLM and the n-C_8 aromatization activity were studied based on microreactor activity test(MAT). The results indicated that pre-calcination at 400-500℃ would help Al-CLM maintain its layer structure with higher order and intactivity during the process of platinum impregnation. A corresponding larger interlayer space was also maintained. The platinum introduced in Al-CLM could interact with the tetrrahedron layer so as to restrain the siliconoxygen tetrahedron from turning over. Therefore,the escape of the structure hydroxyl on the octahedron layer of Al-CLM became difficult so that the structure hydroxyl stability of Al-CLM was enhanced by platinum. A linear relationship between the yield of C_8 aromatics and the structure intactivity of Pt/Al-CLM was found. This relation ship indicates the importance of the interlayer structure of Pt/Al-CLM for n-C_8 aromatization.
出处
《分子催化》
EI
CAS
CSCD
1994年第1期14-21,共8页
Journal of Molecular Catalysis(China)
关键词
铂
铝
催化剂
芳构化
交联蒙脱土
Platinum, Cross-linking montmorillonite, Structure stabilization, Pre-calcination, n-C_8 aromatization.
