Tetraethylorthosilicate precursor solutions with

The synthesis of MCM-22 precursor and MCM-36 Is described in detail elsewhere [8,9].The following illustrates a typical MCM-36 preparation. MCM-22 precursor wet cake (150 g, 42 % solids) was reacted with 1.1 I of the swelling reagent, C,8TMA-OH (29 % aqueous solution of hexadecyltrimethylammonium chloride contacted with hydroxide-for-halide exchange resin) for 96 hours in a steambox. The solid obtained after filtration, washing and air drying contained approximately 40 % solids and 30 % surfactant. The swollen material was pillared with tetraethylorthosilicate, hydrolyzed... 

The first method uses the controlled concurrent hydrolysis of tetraethoxytitanium (IV) and tetraethoxysilane. This procedure has been labeled the mixed alkoxide method. Frequently, the acronyms TET (tetraethyltitanate) and TEOS (tetraethyl orthosilicate or tetraethoxysilane) are used for the respective reactants these are derived from the alternative names tetraethyl titanate and tetraethylorthosilicate. In examples described in patents, the synthesis involves adding TET to TEOS and then combining the alkoxide mixture with an aqueous solution of a SDA, which is typically tetrapropylammonium hydroxide (TPAOH). The resulting precursor mixture is then heated to a temperature of 175 °C to initiate crystallization. Subsequent washing of the crystallized solid with water, drying, and air calcination produces framework titanium-containing silicalite. 

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