石油学会 年会（研究発表会）

Fe-substituted MWW-type zeolites ([Fe]-MWW_MC) were successfully synthesized by a mechanochemically assisted hydrothermal synthesis, termed the mechanochemical method, for the first time and compared with samples prepared by the conventional hydrothermal method ([Fe]-MWW_HT). A mechanochemical reaction between SiO₂ and a-FeOOH, which is the first step of the mechanochemical method, yielded an amorphous Si-Fe composite oxide that consisted of tetrahedrally coordinated Fe species in a SiO₂ network, as confirmed by X-ray diffraction, UV-vis and Fourier transform infrared spectroscopy (FT-IR) measurements. A hydrothermal treatment for crystallization of the zeolite using a thus-prepared amorphous Si-Fe composite as a precursor as the second step led to the formation of [Fe]-MWW_MC zeolites with well-introduced and dispersed Fe species in their framework. The improved homogeneity of the Fe species in [Fe]-MWW_MC resulted in less extra-framework Fe species compared with [Fe]-MWW_HT. The mechanochemical method was thus confirmed as an efficient route for the synthesis of metallosilicates with well-introduced and dispersed heteroatoms in their framework.