Preparation and catalytic testing of mesoporous sulfated zirconium dioxide with partially tetragonal wall structure

Methods were explored to synthesize sulfated mesoporous zirconia with crystalline pore walls of tetragonal crystal structure. The material has been characterized by small and large angle X-ray diffraction, nitrogen physisorption, transmission electron microscopy (TEM) and catalytic tests using n-butane isomerization to iso-butane and alkylation of 1-naphthol with 4-tert-butylstyrene as probe reactions. It has been found that sulfate deposition is crucial for the transformation of a mesoporous precursor with amorphous pore walls into a material with crystalline pore walls maintaining the mesoporous morphology with narrow pore size distributions. TEM shows no ordered stacking of the pores. As a catalyst for acid catalyzed reactions of large molecules, mesoporous sulfated zirconia is superior to microporous sulfated zirconia.