Zeolite decorated highly porous acicular calcium silicate ceramics

Macrocellular calcium silicate (wollastonite) ceramic foams possessing ~86 vol% total porosity were produced from commercial calcium silicate hydrate (xonotlite) nano-size acicular crystals and poly-methyl-methacrylate microbeads (PMMA) (used as sacrificial pore formers). Open cell wollastonite foams had a bi-modal pore size distribution with major modes located ~100 nm due to interparticle porosity and ~100 µm due to the sacrificial pore former. These macrocellular ceramics were then used as a scaffold for MFI type zeolite (silicalite-1) synthesis. Monolayer coffin shaped zeolite crystals (~3 µm size, measured from the c-axis and ~300 nm thickness) were observed with almost full coverage on the inner macro-cell walls. The specific surface area of the components increased from 9.6 m2/g to 108.2 m2/g via zeolite functionalization, leading to components possessing multiscale porosity.