Abstract: High thermal stability Al-MCM-41 was synthesized in-situ on NaOH Na-montmorillonite by using solution
silicate and surface silicate as Si and Al source . The bulk of CTAB can bedecreased and the synthesized sample will be stable with surface silicate
as Si source. While well long-ranged structure Al-MCM-41 can be obtained by using solution silicate and surface silicate as Si and Al source interacting on the CTAB in the synthesis process. The effect of the bulk of CTAB, NaOH
and the acting time of NaOH was discussed through XRD, nitrogen adsorption, heat stability, TEM. The synthesized sample has high thermal stability, and its
specific surface area has more than 800m²/g after heating at 800℃ for 2h or 100m²/g after heating at 1200℃ for 2h.

Key words: MCM-41, montmorillonite, in-situ synthesis