Synthesis of a gallosilicate analogue of high silica,large Port Mordenitel

A high silica (SiO₂/Ga₂O₃ = 42) crystalline mordenite containing gallium (III) in framework positions has been prepared by hydrothermal crystallization at 413 K in the presence of tetraethylammonium bromide. Evidence for the presence of framework gallium in the mordenite lattice is obtained from chemical analysis, XRD, framework IR, solid state MASNMR, thermoanalytical studies, sorption and catalytic activity studies. Chemical analysis and NMR data indicate the absence of significant amounts of aluminium (SiO₂/Al₂O₃ > 2400). An increase in the interplanar spacing and unit cell volume as well as a shift to lower wavenumbers of framework vibrations occurs on gallium incorporation in the mordenite lattice. Ga-mordenite exhibited significant ion exchange capacity. The gallium analogue of mordenite exhibited significant catalytic activity and shape selectivity in the isomerization reaction ofm-xylene.NCL communication No. 5317.