Thermally stable Pt-Al₂O₃ cryogel with high platinum concentration for catalytic combustion

Abstract

The alumina cryogel with 5 mass% platinum was prepared from aluminum sec-butoxide and H₂PtCl₆ through the sol-gel processing and subsequent freeze drying. The cryogel showed higher thermal stability of platinum than the corresponding xerogel and impregnation catalysts at elevated temperatures. Also for the catalytic VOC combustion the cryogel exhibited higher activity than other catalysts. It was revealed that about half of the platinum surface was inside the alumina cryogel, and such encapsulation was considered the principal cause for the higher stability.