Synthesis of zeolites to measure
Researchers at the Consejo Superior de Investigaciones Científicas (csic) have been released a new concept for the synthesis of molecular sieves, based on the use of organic molecules that self-assemble and that can allow something like the "synthesis of zeolites to measure". A first result has been the synthesis of zeolite A with controlled amounts of aluminium, the zeolite A is known for more than 40 years; However, so far was not possible to synthesize with low aluminium content, much limiting the possible applications.
Labour, led by Professor Avelino Corma, director of the Institute of chemical technology (Joint Center of the CSIC and the Polytechnic University of Valencia), is relevant both in scientific and industrial. The zeolites are porous crystalline solids possessing canals and cavities of molecular dimensions and that have application as absorbent and catalysts in numerous processes of industrial interest.
The work is based on the implementation of a new concept in the field of the synthesis of zeolites based on the use of certain organic molecules that possess the ability to autoensamblarse, form dimers (pairs of molecules) that conform to the shape and size of the cavities of the zeolitesthus acting as a template to generate the porosity.
This concept has been applied successfully to the zeolite A, paradigm of the zeolites by its high content in aluminium and its large industrial application. In this way, has managed to synthesize this material in its purely silica form and with controlled amounts of aluminum.
The zeolite A is known for more than 40 years and used in various industrial applications, mainly as absorbent and some separation processes. However, so far was not possible to synthesize with low aluminium content, limiting much other potential applications, such as additive for catalytic cracking catalysts, processes of conversion of methanol to olefins or the separation of olefins and paraffins, among others.
Organic molecules as templates
The authors have synthesized zeolite purely silica, as well as with controlled amounts of aluminium in its composition, in the range appropriate for their application in Catalysis and separation. The study has needed the participation of several experts in organic and inorganic chemistry, crystallography and Catalysis belonging to the Institute of chemical technology, in Valencia, and the Institute of materials science of Barcelona, also of the CSIC.
In a first stage of the work, the authors synthesized organic molecules capable of autoensamblarse and form structures which adapt perfectly to the shape and size of the cavities of zeolite A.
Using these molecules as templates, different samples of A zeolite with controlled aluminium contents were. Catalytic and measures absorption tests have confirmed the potential of these new materials.
The work of the Institute of chemical technology has a high degree of international recognition in the field of Catalysis and synthesis of zeolites. Its director, Avelino Corma, has recently received awards from the American Association of catalysis (Houdry Award), European Federation of catalysis societies (f. Gault Award), and International zeolite Association (Breck Award). The Institute of chemical technology has been patented in the past five years a total of 11 new zeolites and three catalytic processes.
