In one embodiment, a catalyst formulation includes a poison adsorbing
material and a catalyst material. The poison adsorbing material comprises
large particles having an average major diameter of greater than or equal
to about 2.0 micrometers. The catalyst material comprises a precious
metal support comprising small particles having an average major diameter
of less than or equal to about 1.0 micrometers, and a catalyst material
comprising at least one of ruthenium and iridium.