High Potential of Interzeolite Conversion Method for Zeolite Synthesis

Many types of zeolites such as beta (hereinafter, *BEA), CHA, LEV, RUT, and MFI were successfully synthesized by interzeolite conversion of FAU, *BEA, and LEV type zeolites as starting materials under various hydrothermal synthesis conditions. The crystallization rates of zeolites using such starting zeolites were notably elevated compared to rates observed in conventional hydrothermal syntheses using amorphous aluminosilicate gels. This characteristic enhancement in the crystallization rate results from the generation of locally ordered aluminosilicate species (nanoparts) through the decomposition/dissolution of the starting zeolite, resulting in assembly and evolution into another type of zeolite. The structural similarity between the starting zeolite and the final crystallized zeolite is a crucial factor for interzeolite conversion. These findings strongly indicate that the interzeolite conversion route is an attractive strategy for zeolite synthesis and zeolite design will be possible after methods to selectively assemble the nanoparts are established.