High-Performance Catalysts with MSE-Type Zeolite Framework

Advances on the preparation routes to MSE-type zeolites, microporous silicates with a 12-10-10-ring micropore system, are reviewed and some examples of the catalytic application are presented. MCM-68 as the most typical aluminosilicate material with the MSE framework synthesized by using a rigid and bulky diquaternary ammonium cation as the organic structure-directing agent exhibited excellent catalytic performance for hexane cracking and dimethyl ether-to-olefin reactions when it was post-synthetically dealuminated with nitric acid. Variation of the synthetic route provided characteristic aluminosilicate MSE-type materials with the improved catalytic performances for hexane cracking. Dealuminated MCM-68 was efficiently converted to titanosilicate [Ti]-MCM-68, which exhibited high catalytic performance in epoxidation and phenol oxidation. In addition, the pure-silica version of MSE framework, YNU-2, was successfully synthesized by dry-gel conversion method using the same organic cation followed by stabilization via steaming. To the remaining site defects in the stabilized framework of YNU-2, Ti atoms were introduced to give the new microporous titanosilicate [Ti]-YNU-2, which showed very high activity and para-selectivity during phenol oxidation using H2O2 as an oxidant.