Green synthesis of submicron-sized Ti-rich MWW zeolite powders via a novel mechanochemical dry gel conversion in mixed steam environment

In this research, a novel green mechanochemical dry gel conversion method (MDGC) is reported to obtain submicron-sized Ti-rich MWW zeolite. First, titanium and silica sources were milled under milder conditions in a planetary ball mill to construct the uniform SiO2-TiO2 composite powders with higher Ti contents. Subsequently, submicron-sized Ti-rich MWW zeolite powder was prepared via dry gel conversion (DGC) route using the obtained composite under mixed steam environment consisting of water and piperidine. The physicochemical properties of the SiO2-TiO2 composites before and after calcination and corresponding Ti-MWW-MDGC were investigated by XRD, UV–Vis, FT-IR, SEM, XRF, and N2 absorption-desorption. Moreover, Ti-MWW (30)-MDGC exhibited a superior catalytic activity during epoxidation with H2O2 compared with the traditional DGC method, and the conversion of 1-hexene increased from 4.2% to 26.3%. The MDGC method is a promising approach for the green production of various zeolites with higher heteroatom contents, such as TS-1, Ti-Beta and Sn-MWW, etc.