wt 4 high temperature oxidation catalyst 4 pt al 2 o 3 pt ceo 2 catalyst dinitrodiamine platinum solution was added to cerium oxide powder in such a proportion that the pt amount was 1 5 wt after stirring well the mixture was dried in an oven at 150 u00b0 c for 3 hours and calcinated at 800 u00b0 c for 4 hours so as to obtain a pt ceo 2 catalyst powder i 300 g of this powder i 700 g of the powder a and 1000 g of the alumina sol were introduced into a ball mill pot and crushed for 8 hours to give a slurry j the slurry j was coated onto a monolithic substrate base and after drying calcinated at 400 u00b0 c for 2 hours to give a catalyst k the coating amount of the catalyst k is set at 120 g l when the pt amount is 1 1 3 wt to 160 g l when the pt amount is 0 75 1 wt 5 low temperature oxidation catalyst 1 pt al 2 o 3 catalyst dinitrodiamine platinum solution was added to 1000 g of active alumina powder having u03b3 alumina as its main constituent after stirring well the mixture was dried in an oven at 150 u00b0 c for 3 hours and calcinated at 400 u00b0 c for 4 hours so as to obtain a pt al 2 o 3 powder l 1000 g of this powder a and 1000 g of an alumina sol.