화학공학소재연구정보센터
Catalysis Letters, Vol.119, No.1-2, 134-141, 2007
Pt-Al2O3 cryogel with high thermal stability for catalytic combustion
The cryogel catalyst of platinum on alumina was prepared from aluminum sec-butoxide and H2PtCl6 through the sol-gel technique and subsequent freeze drying. The cryogel catalyst showed higher thermal stability of platinum than the corresponding xerogel or impregnation catalysts, which was ascribed to the more intimately developed platinum-alumina interaction accompanied by the encapsulation of the metal into the alumina cryogel. It was also shown that platinum accessibility was higher on the cryogel than on the xerogel despite the higher thermal stability of the metal on the formed than on the latter. For the VOC combustion, the cryogel exhibited higher activity than the xerogel and impregnation catalysts. Also for the methane combustion the cryogel showed higher activity, although it showed lower activity than the impregnation catalysts above 600 degrees C. By the addition of ceria as an additive to the cryogel catalyst, the CH4 combustion activity was improved especially in the temperature region above 600 degrees C.