Microporous acidic oxide with catalytic properties itq-18

Abstract

The invention concerns a microporous crystalline material, with a characteristic X-ray diffractogram, made up by oxygen tetrahedra and one metal (T and T ) with the possibility of introducing surface acidity produced by the substitution in the network of some T cations (normally Si ) by T cations (normally Al ), which gives rise to a structural charge deficiency which can be offset by protons, Brönsted acidity, and/or cations with a high charge-radium ratio, Lewis acidity. The method of preparation is based on the modification of the laminar structure of a mixed oxide (normally SiO , Al O ) synthesized from a gel treated under controlled hydrothermal conditions, intercalating organic molecules with a proton-acceptor group and a long hydrocarbonic chain between its laminae. The intercalated material has laminae with a significant separation between them due to the presence between them of the organic chains. The swollen material is then treated in order to separate and disperse the laminae. The final washing and subsequent calcination gives rise to a microporous material with a high external surface, the object of this invention.