Phase transformation of rice husk ash in the synthesis of ZSM-5 without organic template

Phase transformation of rice husk ash in the synthesis of zsm-5 without organic template at various crystallization times has been studied. zeolite has been synthesized using the hydrothermal method at 175 °c with molar ratio 10na2o : 100sio2 : 2al2o3 : 1800h2o with addition of silicalite-1 as seed. solids were characterized using x-ray diffraction (xrd),infrared (ir) spectroscopy and scanning electron microscopy (sem) techniques. analysis of the results of xrd and ir spectroscopy indicated that zsm-5 crystalstarted to form at 12 h of crystallization time,reaching high crystallinity after 24 h. with a crystallization time of more than 48 h,the zsm-5 crystals had completely transformed into more stable quartz phase. results indicated that phase transformation has occurred,in which an amorphous phase of rice husk ash has been transformed to zsm-5 crystal phase during the early crystallization stage and continued to transform to disordered α-cristobalite phase and lastly quartz phases. sem showed that the morphology of the zsm-5 crystal was of an irregular hexagonal shape with particle size distribution around 3-7 μm. © 2012 published by lppm itb.