Preparation of MCM-41 with high structural stability

MCM-41 molecular sieves with high structural stability and long-range order were synthesized using ethylamine (EA) as an additive instead of mineralizers such as NaOH and TPAOH. X-ray diffraction showed that the EA/CTAB (cetyltrimethylammonium bromide) ratio was the critical factor that determines the degree of ordering in MCM-41, and an EA/CTAB ratio of 0.2 or 0.5 produced the highest long-range order. The samples had walls approximately 2 nm thick, which is the highest level ever reported. Therefore, they did not lose their structure entirely even after heat treatment at 1000 °C. Together with the effect of the EA/CTAB ratio, the textural mesoporosity, as confirmed from the N2 adsorption–desorption isotherm analysis, suggests the EA participates in the templating process of the mesostructure.