Incorporation of Silicon into AlPO-5 Framework Sites: Higher Thermal Stability and Lower Extra-Framework Aluminum Concentration

摘要: Diffuse reflectance spectroscopy was used to investigate the structural modification of AlPO-5 microporous aluminophosphate synthesized in presence a silicon source and subjected calcination air. Extra-framework aluminium species, formed upon expulsion from framework, are detected by DRS because they involved aluminium-oxygen charge transfer transitions. Impregnation calcined SAPO-5 samples with ethanolic acetylacetone converted all extra-framework atoms distorted symmetry highly ordered symmetry, as evidenced distinct well-defined 280 nm band DR spectra. The intensity absorption is much higher than those different content. This an indication ofa considerably amount AlPO-5. Washing treated hot ethanol leads extraction some complexed aluminium. progress could be monitored both UV-vis spectrophotometry.