Preparation of non-permselective sulfated zirconia catalytic membrane for use in a catalytic membrane reactor

Abstract

In this work, for the first time, preparation of non-permselective sulfated zirconia catalytic membrane on α-alumina support was investigated. In-house synthesized sulfated zirconia nanopowder calcined at 650°C was used for the preparation of catalytic layers. Aluminum triisopropylate and silica nanopowder were utilized to synthesize appropriate coating sols and facilitate layers fabrication via the sol–gel method. The catalytic layers with gradient composition were coated on the surface modified support. The results showed that the sol with strong acid media (pH<2) could not be used for the preparation of layers. However, the coating sol with pH of 3.5 was completely stable, and sintering of the fabricated layers could be done at low temperatures. The prepared catalytic membrane had suitable porous and crack-free microstructure with desirable crystalline phase, indicating proper sintering operation and successfully preventing the tetragonal to monoclinic phase transformation due to the appropriate applied SZ–Al2O3–SiO2 composite structures.