The effect of preparation methods for promoted platinum over alumina to CO oxidation reaction

Abstract

The activity of platinum promoted with ceria over alumina was investigated. The presence of ceria doped in alumina by sol gel method dramatically increased the activity of platinum over alumina at a low range of temperatures. T1/2 of the 5%Pt/5%Ceo2/Al2O3 was 145๐C, while T1/2 of the 5%Pt over commercial alumina was 170๐C. This may result from the oxygen storage properties of ceria. Furthermore, sol gel method offered the uniformity to the final metal oxide and in turns led to a better activity to CO oxidation comparing to that of the other catalyst preparation technique. Finally, iron oxide was used as an oxygen storage compound. However, the result was not as good as the result from ceria. The activity of platinum over alumina catalyst containing 5%Fe2O3 increased about 12% comparing with that of platinum over commercial alumina. Interestingly, CO was completely converted to CO2 at temperature of 180๐C for all catalysts. Keywords: CO oxidation, promoted platinum over alumina catalyst, oxygen storage, sol gel method, impregnation.