Skeletal isomerization of hydrocarbons over zirconium oxide promoted by Platinum and Sulfate Ion

Several methods have been developed and applied in recent years in the characterization of the structure of microporous materials, in general, and of pillared clays, in particular. In the present article, the latest results obtained in the control of the microstructure developed in alumina‐pillared clays and various approaches used to the evaluation of the porosity of these materials are reviewed. These include the control of the microstructure developed in pillared clays by adjusting the several parameters involved in the synthesis process, and the evaluation of the porosity of pillared clays. Emphasis is given to the methods to evaluate the pore size and pore size distribution (PSD) of these materials. Two separate sections are devoted to review mathematical modeling studies and 129Xe NMR spectroscopy of physisorbed Xe to investigate the microporous structural properties of these materials.

Recent Advances in the Control and Characterization of the Porous Structure of Pillared Clay Catalysts

There have been significant developments in the pillaring of lamellar ionic materials, and the resulting zeolite-like pillared derivatives have built a large family of microporous materials. This review focuses on the host−guest reactions involved in the preparative procedures. Furthermore, approaches to the modification of the low-dimensional porous network structure are discussed.

Preparation and Properties of Two-Dimensional Microporous Pillared Interlayered Solids

Dynamic modification of surface acid properties with hydrogen molecule for zirconium oxide promoted by platinum and sulfate ions

Acidity in pillared clays is a broad topic, and one which has been reviewed before [1-3]. Since it is difficult to be exhaustive, the present contribution is divided in two parts. The first one tries to establish relationships between observed acidity and structural data in the only case which is sufficiently understood to date, i.e., [Al-13] in smectite clays. The second part is concerned with the acid catalytic properties of pillared clays. They are classified according to the types of reactions. While most references are concerned with [Al-13]@smectites, other systems will be considered too as the need arises.

Acidity in pillared clays: origin and catalytic manifestations

The effect of spilled-over hydrogen on the activity of montmorillonite pillared by aluminum oxide for conversion of trimethylbenzenes

The effect of Pd loading on the catalytic activity of montmorillonite pillared with alumina (Al-mont) was investigated. The catalyst deactivation was prevented by loading a small amount of Pd on Al-mont and using H 2 as a carrier gas, although the initial activity was reduced. Since the mixing of 0.5 wt% Pd Al 2 O 3 with Al-mont gave similar effects to those from the Pd loading, the stabilization of activity in the presence of both Pd and H 2 may be caused by spilled-over hydrogen. By comparison, the activity of H-Y was not stabilized under the same condition. The strong acid sites of Al-mont, which were mostly Lewis acidic, decreased by Pd loading in the atmosphere of H 2 stream, whereas those of H-Y changed little, due to Bronsted acidity. These results suggest that Lewis acid sites can play a very important role in the stabilization of the catalytic activity by spilled-over hydrogen.

T. Fuse

Papers

The effect of spilled-over hydrogen on the activity of montmorillonite pillared by aluminum oxide for conversion of trimethylbenzenes

The Effect of Spilled-Over Hydrogen on the Activity of Montmorillonite Pillared by Aluminum Oxide for Conversion of Trimethylbenzenes.