Effect of the preparation method on the reduction behavior of gold catalysts supported on ceria dopei with FeO_x: assignment and kinetic parameters of the individual reduction processes

摘要

Gold catalysts supported on ceria doped with FeO_x were studied. The mixed supports were synthesized by two methods: co-precipitation (CP) or mech-anochemical activation (MA). Depending on the preparation method, the structure of the mixed supports was different: using CP, only a Fe-modified ceria phase exists, while supplementary to ceria, a second hematite phase presents in the case of MA preparation. The reduction behavior of the gold catalysts and the initial supports was commented on the basis of hydrogen consumption and kinetic parameters of the individual reduction process. Their assignment was proposed using also the data of Mossbauer measurements. It was established that the existing separate Fe-containing phase could participate in a redox process at relatively low temperatures (LTs) and it could be promising for improvement of the catalytic performance of the mechanochemically prepared gold catalyst.