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Title: Preparation and thermal properties of Zr-intercalated clays

Montmorillonites intercalated by zirconium macrocations have been prepared. Diffusion of the Zr cations within the particles of clay controls the rate of ion exchange, and hence the distribution of the Zr pillars. This effect accounts for the influence of particle size on the degree of exchange, the surface area, and the thermal stability of the pillared clay. The thermal stability of the Zr clays prepared under these conditions is limited to 973 K in dry air. The changes in microporosity, evaluated from nitrogen adsorption using the equation of Dubinin, show that collapse of the structure occurs by sintering of the pillars. This sintering can be decreased by doping the pillars with rare earth cations. The resulting material then retains a surface area of 180 m{sup 2}/g after calcination at 1023 K in dry air, and is more acidic than the corresponding Zr-clay.
Authors:
; ; ;  [1] ;  [2]
  1. (Laboratoire de Chimie Organique Physique et Cinetique Chimique Appliquees, Montpellier (France))
  2. (Laboratoire de Chimie Physique, Montpellier (France))
Publication Date:
OSTI Identifier:
6843771
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Catalysis; (USA); Journal Volume: 119:1
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; CATALYSTS; CHEMICAL PREPARATION; MONTMORILLONITE; PHYSICAL PROPERTIES; STABILITY; ZIRCONIUM; ION EXCHANGE; ADSORPTION; CALCINATION; CATALYTIC CRACKING; DIFFUSION; DOPED MATERIALS; MICROSTRUCTURE; NITROGEN; PARTICLE SIZE; PETROLEUM FRACTIONS; PH VALUE; POROSITY; RARE EARTHS; SINTERING; SURFACE AREA; VISCOSITY; CHEMICAL REACTIONS; CLAYS; CRACKING; CRYSTAL STRUCTURE; DECOMPOSITION; ELEMENTS; ENERGY SOURCES; FABRICATION; FOSSIL FUELS; FUELS; INORGANIC ION EXCHANGERS; ION EXCHANGE MATERIALS; MATERIALS; METALS; NONMETALS; PETROLEUM; PYROLYSIS; SIZE; SORPTION; SURFACE PROPERTIES; SYNTHESIS; THERMOCHEMICAL PROCESSES; TRANSITION ELEMENTS 020400* -- Petroleum-- Processing