Synthesis and characterization of micro-mesoporous MCM-41 using various ionic liquids as co-templates

• Synthesize high quality MCM-41.
• Investigation the effects of ionic liquid surfactants on the final products.
• Using different ionic liquid to form micro/mesoporous silica.

Micro-mesoporous silicate solids with increasing intersection network of porous structure have been successfully prepared by using mixtures of cteyltrimethylammonium bromide (CTAB) and some cationic ionic liquids as co-templates. N-butyl-Dabco bromide [N-buDabco]Br, N-butylpyridinium bromide [N-bupy]Br and N-butyl-hexamethylenetetramine bromide [N-buHMTA]Br were used as co-templates under the same synthesis conditions. All synthesized solids shown narrow pore size distribution in micropore region; furthermore, aromaticity and steric hindrance of the three unique ionic liquids on the final products have been investigated; micro-mesoporous silicate solid prepared by [N-buHMTA]Br showed significant decrease in the surface area and pore volume comparing to the other ionic liquids, which is may be due to the steric hindrance of used ionic liquids. The use of ionic liquids with aromatic core instead of aliphatic core did not show major effects on the characteristic features of final product. The synthesized products were characterized via IR, XRD, N2 adsorption-desorption analysis and SEM. The results showed MCM-41 solids with total BET surface area of 1035, 1028 and 678 m2 g−1 have been synthesized.

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