Novel catalyst supports with lamellar and hierarchical porosity

Geopolymers are synthetic alkaline alumino-silicates that may beregarded as the amorphous counter part or precursor of crystalline zeolites. At the atomic scale, the geopolymer network is formed by SiO4 and AlO4 tetrahedra connected by oxygen corners: the tetrahedra form Si-O-Al-O rings of various sizes and endow the geopolymer matrix with ion exchange properties. These materials show properties ranging from those characteristic of ceramics, cements, zeolites or refractories. Geopolymers are intrinsically mesoporous and a hierarchical pore system may beobtained combining meso and macropores In this work, water-based freeze casting (or ice-templating) is used to prepare porous geopolymers with main unidirectional oriented pores and a high open porosity, where the final component results in a lamellar structure. The aim of this study is to produce and characterize novel catalyst supports of different geometries and dimensions, with lamellar macroporosity and geopolymer intrinsic mesoporosity.