Paper number n n-1 Structure of Mesoporous MCM-41 Prepared from Rice Husk Ash

Mesoporous silicate particles, called MCM-41 were produced from rice husk ash generated by a biomass fired power plant. More than 95 % of amorphous silica was extracted from rice husk ash by acid leaching. The RHA_MCM-41 particles were synthesized using sodium silicate prepared from rice husk ash and commercial sodium silicate as a silica source and hexadecyltrimethylammonium bromide (CTAB) as an organic template. The mixture was stirred at room temperature for 48 h and then calcined at 550 °C for 4 h. The crystallinity characteristics and the porosity properties of MCM-41 synthesized from rice husk ash were similar to those of MCM-41 synthesized from commercial silica. The results from the X-ray diffraction (XRD) indicated the well-defined crystallinity of the synthesized MCM-41. The diameters determined from the Scanning Electron Micrographs of fine silica particles and the MCM-41 particles were approximately 50 µm and 0.3-0.5 µm, respectively. The images from Transmission Electron Microscope (TEM) of the MCM-41 particles confirmed the arrangement of hexagonal patterns, which is the distinctive characteristic of M41S families. The Brunauer-Emmett-Teller (BET) surface area of the RHA_MCM-41 particles determined from nitrogen adsorption isotherm was about 730 m2g-1 and its pore sizes estimated from the TEM images agreed very well with the pore sizes calculated from the data of nitrogen isotherms. The plots of pore size distributions using the Barret-Joyner-Halenda (BJH) method showed quite narrow pore diameter distributions, centered around 2.2 nm, corresponding to the TEM results