Finely divided noble metal-refractory metal alloys and methods for making them are disclosed. As catalysts these alloys have greater activity than a catalyst of the same unalloyed noble metal and may be advantageously used as electrodes for fuel cells particularly when supported. The method for making supported catalysts involves a simple and inexpensive procedure for converting a supported, finely divided noble metal catalyst to the desired alloy. In a preferred embodiment the process includes intimately contacting the supported noble metal catalyst with a finely divided refractory metal oxide, the metallic component of which is capable of enhancing the activity of the catalyst when alloyed therewith, and then heating to a sufficiently high temperature, preferably in a reducing atmosphere, to reduce the oxide and simultaneously form a finely divided, supported alloy of the noble metal and the metallic component of the oxide.