Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Chemical tuning of properties of porous and crosslinked oxide-pillared layer structured materials

Using new synthetic routes, oxide pillared materials have been prepared and successful development of novel and generalizable strategies and synthetic methods ensued for obtaining oxide-pillared materials of high surface area or with other original properties. The synthetic routes conceived were appropriate for the preparation of several series of oxide-pillared layered structures of high surface area. Control of the synthetic process provides a method of obtaining micro-porous and meso-porous materials of variable surface area, pore size and volume, and different total acidities. Textural and surface characteristics can thus be tailored by adequate control of the preparative conditions. Detailed characterization of new and existing materials was carried out via their thermochemistry and their spectroscopic properties. X-ray absorption fine structure analysis of the chromia pillars in chromia pillared phosphates, and examination of the dehydration processes in aluminium oxyhydroxide intercalated clays and in layered double hydroxides have been carried out. Atomic force microscopy has furnished detailed images of host layered solids and, most recently, of an iron-alumina pillared clay. Results were published on the use of oxide pillared layered structures as template solids for restricted growth of clusters and polymers. Hybrid catalyst materials in which organometallic/coordination compounds act as pillars in the pillared layered solid (PLS) interlayer region and subsequently act as catalytic centres were developed from bifunctional ligands. With respect to chemical and electrochemical properties, in addition to providing a description of their acidity through dehydration/dehydrogenation reactions, compounds have been tested as deep oxidation catalysts for the destruction of chlorinated hydrocarbons and chlorofluorocarbons, as hydrodesulfuration catalysts and for their activity in the degradation of nitrogen oxides. The environmental significance of the last three reactions cited in easily recognised.

Reported by

Université Montpellier II
34095 Montpellier
France
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