A process of preparing a product gas mixture comprising CO and H2 from a light hydrocarbon and O2 mixture is disclosed. The process includes contacting a reactant gas mixture comprising a C1-C5 hydrocarbon and a source of molecular oxygen with a catalytically effective amount of a supported catalyst comprising nickel and rhodium. The catalyst and reactant gas mixture is maintained at catalytic partial oxidation promoting conditions of temperature and pressure during the contacting period, which is preferably 10 milliseconds or less. Certain preferred catalysts comprise an alloy of about 1-50 weight percent nickel and about 0.01-10 weight percent rhodium on a porous refractory support structure.