Synthesis of Monolithic Zeolites with Macropores

Abstract

Monolithic polycrystalline zeolites with through-macropores were prepared by steam treatment of bimodal porous silica gel monolith in the presence of tetrapropylammonium hydroxide, where the bimodal porous silica gel was prepared by inducing phase separation during sol-gel process. The silica skeleton with mesopores was transformed into polycrystalline zeolites maintaining continuous macropore morphology and monolithic shape. In the zeolites, there are three different pores arranged hierarchically: through-macropores originally existed in the precursor silica gel, small macropores at interstitial of zeolite crystallites, and micropores in zeolite framework.