u02dc 3 a suitable process for preparing the pt u2014 ru metal oxide catalyst of the present invention comprises the following steps a impregnating a metal oxide in an aqueous solution containing pt ions and ru ions having an amount so that said mixture oxide is subjected to an incipient wetness impregnation and b heating the resulting impregnated mixture oxide from step a so that substantially only pt and ru ions in said aqueous solution are deposited on said metal oxide preferably the amount of said aqueous solution in step a enables said metal oxide to be impregnated with 0 1 5 0 of pt ions and 0 1 5 0 of ru ions based on the weight of said metal oxide said incipient wetness impregnation comprises measuring the moisture content ml g of said metal oxide prior to said impregnating and preparing a suitable volume of an aqueous solution of pt metal salt and ru metal salt while under mixing said aqueous solution is dripped into said metal oxide in a container which is immediately absorbed by said carrier upon completion of addition of all aqueous solution said metal oxide is still in the form of a powder but with slightly wetted surfaces preferably said heating in step b comprises drying said incipient wetness impregnated metal oxide at 100 150 u00b0 c and calcining said dried metal oxide at 400 1000 u00b0 c preferably at 800 950 u00b0 c another suitable process for preparing the pt u2014 ru metal oxide catalyst of the present invention comprises the following steps a immersing a metal oxide in an aqueous solution containing pt ions and ru ions b adjusting ph value of said aqueous solution so that pt ions and ru ions are adsorbed on surfaces of said metal oxide and.