SYNTHESIS OF THERMALLY STABLE MCM-41 AT AMBIENT-TEMPERATURE

A new process to synthesize thermally stable mesoporous molecular siev es of MCM-41 structure based on delayed neutralization at ambient temp erature was investigated. All samples synthesized by this new method h ave BET surface areas of about 1100 m(2)/g and possess high thermal st ability up to 900 degrees C. Higher crystallinity and less lattice con striction after calcination were observed for samples with a longer ag ing period. Those samples with aging time longer than 10 days exhibite d four characteristic XRD peaks of MCM-41 both before and after calcin ation at 560 degrees C. The N-2 adsorption-desorption isotherms of the calcined samples showed larger average pore size and more homogenous pole size distribution. The method was also successfully applied to th e synthesis of MCM-41 with different surfactants of hydrocarbon length with 10-18 carbons and proves to be a simple route for obtaining ther mally stable MCM-41 at room temperature.