DRY IMPREGNATION OF PLATINUM ON A CARBON SUBSTRATE

摘要

This invention provides a method for preparing particles of a platinum metal element on a carbon substrate. An aqueous solution of a platinum metal element complex is prepared by dissolving the platinum metal element complex in water not exceeding the pore volume of the carbon substrate to be impregnated. The pH of the aqueous solution is adjusted if necessary, to a value of less than 2. A carbon substrate is dry impregnated with the aqueous solution and dried at ambient conditions. The platinum metal complex-loaded substrate is heated to a temperature of about 200° to 300°C under reducing conditions. The platinum metal particles so formed are preferably about 15 to about 25A in diameter. The carbon substrate is used to make a carbon membrane or electrode having highly dispersed platinum metal elements of at least 120 m² Pt/g Pt at platinum metal loadings of at least 20%.