Studies of preparation and stability of Au/Fe2O3 catalyst for CO oxidationat ambient temperature and moisture

The catalytic performance of CO oxidation at ambient temperature and moistu re over Au/Fe2O3 catalysts prepared by different methods was studied. It wa s found that the stability of the catalysts was greatly changed with the va riation of the preparation methods, the kind of precipitant, calcination te mperature, and Au loading. The sample of 3%Au/Fe2O3 prepared by adding HAuC l4 and Fe-2(NO3)(3) with K2CO3 or Na2CO3 as the precipitants, calcined at 2 50-350 degrees C in air for 3 h has the best stability and the best ability of resisting moisture, that is, the sample can maintain CO complete conver sion at 25 degrees C and ambient moisture for at least 430 h. The XRD resul ts indicate that the stability is inversely proportional to the metallic go ld and alpha-Fe2O3 particle sizes, and the chemical states of gold and iron were the main controlling factors of the stability of Au/Fe2O3.