Glinokrzemofosforany i ich wybrane zastosowania

At the end of 20-th century B.M. Lok et al. discovered and next patented a new class of solids. They called it silicoaluminophosphates (abbreviation - SAPO) because of the chemical constitution of these molecular sieves. These new materials consist of tetrahedral units of silicon, aluminium and phosphorous oxides arranged in a manner that can be regarded as silicon substitution into hypothetical aluminophosphate (AlPO4) framework. SAPOs are prepared under mild hydrothermal conditions from gel containing precursors of phosphorous, aluminium, silicon oxide and a structure directing template (mostly amines and quaternary ammonium compounds). Unique properties of SAPO molecular sieves such as possibility of acidity control of solids in a wide range during synthesis and shape selectivity of catalyst based on silicoaluminophosphate aroused interest of scientists, who started research of the SAPO's properties, new applications and new, improved methods of synthesis of these molecular sieves. In this paper article we have described properties of silicoaluminophosphates molecular sieves, mechanism of Si incorporation into hypothetical AlPO4 framework and have described known classic methods of the SAPO's synthesis presented by Lok et al. as well as improved ("rapid" method, non-aqueous medium, with surfactant and dry gel conversion). At the end we have presented two of many possible applications . hydroisomerization of n-paraffins and synthesis of olefins using "Methanol To Olefin Process".