Extrusion of zeolites: Properties of catalysts with a novel aluminium phosphate sintermatrix

A novel type of mechanically strong zeolite extrudates is introduced, in which the zeolite crystals, here ZSM-5, are embedded in a sintermatrix of aluminium phosphate with the crystal structure of tridymite. The pore size distribution in the matrix can be tailored through both, the choice of the size of the embedded particles and their amount in the extrudates. At zeolite concentrations of 50% (w/w) or higher, the mean pore diameter of the matrix (Dpore) depends on the zeolite crystal size only, and amounts to Dpore ≈ 0.25Dparticle. Other than conventional matrices on alumina basis, the AlPO4 matrix does neither provide catalytic self-activity, nor does cause any alumination of the zeolite framework.

Graphical abstractA novel type of strong zeolite extrudates is introduced, in which the zeolite crystals are embedded in a sintermatrix of AlPO4 with tridymite structure. The pore size distribution can be tailored through choice of the size of the embedded particles and their amount in the extrudates. Other than alumina matrices, the AlPO4 matrix does neither provide catalytic self-activity, nor does is cause alumination of the zeolite.Figure optionsDownload full-size imageDownload as PowerPoint slide