Al-, Al,Zr-, and Zr-Pillared Montmorillonites and Saponites: Preparation, Characterization, and Catalytic Activity in Heptane Hydroconversion
- 作者：Moreno ; S. ; Kou ; R. Sun ; Molina ; R. ; Poncelet ; G.
- 关键词：Al-pillared clays ; Zr-pillared clays ; Al ; Zr-pillared clays ; pillared montmorillonites ; pillared saponites ; hydroconversion of heptane
- 刊名：Journal of Catalysis
- 出版年：1999
- 期刊代码：97_00219517
- 类别：ce
- 出版时间：February 15, 1999
- 卷：182
- 期：1
- 页码：174-185
- 文件大小：143 K
摘要
Zr- and Zr,Al-pillared smectites have been prepared and characterised by X-ray diffraction and nitrogen sorption measurements. The residual cation exchange capacities and the acid contents have been determined. Hydroconversion of heptane over Pt-impregnated samples was used to evaluate their catalytic properties. The results were compared with those obtained over Al-pillared forms of the same smectites. For the Zr-pillared clays, mixtures of pillared and unpillared fractions were obtained in proportions depending on the preparation conditions. The pillared fractions exhibited poorer thermal resistance than the corresponding Al-pillared forms. Mixed Al,Zr-pillared clays behaved much like Al-pillared clays. The conversion of heptane over the Zr-pillared montmorillonites was substantially enhanced with respect to the Al-pillared analogues, due to the enhanced hydrogenolysis on platinum. Isomerisation activity at the opposite drastically decreased. These changes were less pronounced in the case of the pillared saponites. Zr-pillared saponite with low tetrahedral charge showed an intermediate behaviour.