Multifunctional Mesoporous Inorganic Solids

1. Introduction. There is much interest in the general subject of porous inorganic materials with respect to their use as sorbents or catalysts. Such inorganic solids may be microporous, mesoporous or macroporous according to the sizes of the pores within the solid. Often there is a range of pore sizes within any given solid and so there is special interest in the synthesis, characterisation and application of porous inorganic solids with well defined pores. Pores of diameter larger than 50 nm are generally termed macropores. Those with diameters of less than 2 nm are micropores and pores of intermediate size are called mesopores. Solids, which contain only mesopores, are correctly called mesoporous but very often there is a combination of different types of porosities within one given solid. The synthesis, characterisation and application of microporous solids is much more advanced than is the case with mesoporous substances. Moreover, the synthesis of crystalline mesoporous materials is one clear goal for the future but which has not been attained so far. Consequently, it is of interest to examine the current state of our knowledge of microporous materials and to examine how this may apply to mesoporous materials. Both catalytic and sorption processes could benefit from studies of mesoporous solids because the mesopores could permit diffusion of larger reactants or products than is the case in microporous materials. 2.

Zusammenfassung
Proceedings of the NATO Advanced Study Institute, Sintra, Portugal, April 5-17, 1992

Inhalt
I. The Measurement Of Porosities.- The measurement of mesoporosity.- About surface area and porosity measurements in pillared clays.- New theoretical approaches to characterization of mesoporous solids.- Nitrogen adsorption on zirconium bis monohydro genphosphate with ?-type structure.- Study of the accessible micropore volume in pillared montmorillonites.- II. Porous Crystalline Materials.- Hydrothermal synthesis and porous crystals.- Pores in tetrahedral frameworks.- Realistic simulation of mesoporous materials by random packing arrays of hard spheres.- Synthesis and characterization of vanadium oxide layered compound.- SHS The new method of different inorganic materials production.- Treatment of dehydrated Na-Y zeolite with the heteropolymetallic products of transmetation reactions.- Textural characterization of PILC montmorillonite pillared with binary oxides LaNiOx.- Structure direction in zeolite synthesis.- III. Pillared Layered Solids.- Mesoporous pillared layered materials.- Problems related to the pillaring of ?- and ?-layered M(IV) phosphates with large cations or with covalently bonded diphosphonates groups.- The synthesis, characteristics and applications of layered double hydroxides.- Structure and texture properties of calcined layered Mg, Al double hydroxides.- The microstructure of layered double hydroxides modified by controlled anion intercalation.- Shape-selective intercalation reactions and chemical sensing in layered metal phosphates and phosphonates.- Micro- and mesoporous clays pillared with SiO2-TiO2 mixed oxide sols.- Mesoporous clays and pillared clays as liquid phase alkylation catalysts.- Oxide-pillared layered ?-metal(IV) hydrogen phosphates.- Synthesis of porous and crosslinked layered phosphates by the intercalation oforganometallic precursors.- IV. Sol-Gel Methods.- Sol-gel synthesis of multifunctional mesoporous materials I. Metal-organic precursors.- Sol-gel synthesis of multifunctional mesoporous materials II. Inorganic precursors.- Porous structures of sol-gel Al2O3(-3SiO2) gels and glasses infiltrated by aqueous solutions.- V. Other Methods of Characterising Inorganic Materials.- Solid state nuclear magnetic resonance spectroscopy.- Solid state 27Al NMR studies of LDH-intercalates.- Characterisation of porous solids using small-angle X-ray and neutron scattering.- Pulsed ESR applied to microporous and mesoporous inorganic solids.- Electrochemical characterisation of porous materials: Electrokinetic potential measurements.- VI. Some Applications of Multifunctional Mesoporous Inorganic Materials.- Pillared acid-activated clays: Synthesis, characterisation and application to chlorophyll adsorption.- Studies of clay modified electrodes.- Microporous-mesoporous metal-oxygen cluster compounds: Ion exchange, structure retention and the oxidative dehydrogenation of isobutyric acid.- Chemically modified electrodes and mesoporous inorganic materials.- Sol-gel processed coatings.