Novel synthesis of ordered MCM-41 titanosilicates with very high titanium content via ultrasound radiation

A novel synthetic strategy has been developed for the fabrication of mesostructured titanosilicate with very high titanium content. By the combination of ultrasound radiation and a separate hydrolysis procedure, highly ordered MCM-41 titanosilicates can be synthesized within 3 h from gels with Ti/Si ratios up to 1. The physicochemical properties of the materials were characterized by means of XRD, TEM, FT-IR, UV-Vis DRS, ²⁹Si MAS NMR, and liquid nitrogen adsorption-desorption measurements. The results suggested that during crystallization, sonication re-dispersed and accelerated the condensation of inorganic species, and resulted in more condensed pore walls compared to those synthesized with the conventional methods. The presence of silica and ultrasound radiation remarkably suppressed the aggregation of titanium species, thus, at the medium titanium level, a relatively homogeneous dispersion of titanium within the MCM-41 framework was attained.