(653c) Synthesis of Mesoporous Zsm-5 Composites Using A Single Template

In many catalytic applications of zeolites, diffusion limitations and pore blockage are serious limitations to their efficient use. A well-connected, hierarchical system of micro- and meso-/macropores may solve those problems. Thus, meso-structured zeolites have attracted significant attention. In recent years, due to the development of supra-molecular templating techniques (such as using the tri-block copolymer P123), promising methods were developed to introduce mesopores into zeolites. However, the practical implementation of such materials is limited, since the templates are often expensive or the methods tend to be complicated.

Here, we report a facile one-pot method to synthesize a composite of ZSM-5 and a mesoporous matrix (denoted as TUD-M) by using only one organic templating/scaffolding molecule (TPAOH). Micro- and mesopores form separately under different conditions, allowing an optimized control over the porosity. Our design distinguishes itself by its simplicity, low cost, and flexibility. TEM reveals that TUD-M is a composite with fairly uniform zeolite crystals embedded in a mesoporous matrix. The crystal sizes observed by TEM are in good agreement with dynamic light scattering results. 27Al MAS NMR demonstrates that Al is entirely incorporated in the framework.