TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The hydrocarbon is (un)saturated 5C or less hydrocarbons.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The gas for activating catalyst precursor comprises preferably 20 mol.% or more of hydrocarbon. The gas optionally comprises hydrogen, nitrogen, argon and/or helium, preferably hydrogen and the molar ratio of hydrocarbon to hydrogen is 0.04-10:1.Preferred Process: The catalyst precursor is activated at 300-1000 degrees C. The catalyst precursor is prepared by impregnating the support with a solution of cobalt salt such as cobalt nitrate, acetate or oxalate by sol-gel method such that it contains 0.05-3 mol.% of cobalt and 20 weight.% or less, preferably 0.02-10 wt.% of carbon. The catalyst precursor is calcined at 300-500 degrees C before activation. The activated catalyst is pacified by treatment in a reduced oxygen atmosphere for at least 30 minutes. The atomic ratio of carbon to oxygen in the feedstock of partial oxidation of hydrocarbon is 0.9-5:1. The oxygen is present in the form of mixture of oxygen and water, oxygen and carbon dioxide, or oxygen, water and carbon dioxide. The oxygen is diluted with nitrogen, argon or helium. SPECIFIC COMPOUNDS - The hydrocarbon is specifically claimed as methane or ethane. The support is specifically claimed as alumina, modified alumina, silica, modified silica, beta-aluminate, magnesia, titania, spinel oxide, zirconia, zeolite or carbon.    EXAMPLE - Alumina support (1 g) was impregnated with 0.2 M barium nitrate solution (1 ml). The mixture was dried at 120 degrees C for 4 hours, followed by calcination at 600 degrees C for 4 hours to obtain a barium oxide-modified support. The modified support (1.05 g) was then impregnated with 1 M cobalt acetate solution (1 ml) for 4 hours and dried at 100 degrees C for 3 hours. The resulting solid was calcined at 700 degrees C and cooled to room temperature to give the oxide precursor of cobalt catalyst.    The precursor was treated with 30 ml/minute of 20% ethane/hydrogen at 750 degrees C for 2 hours and then cooled to room temperature. The activated catalyst was treated with oxygen/nitrogen (1%) at room temperature for 2 hours. Activated catalyst (0.1 g) was placed in a quartz tube, heated to 900 degrees C in static 20% ethane/hydrogen and held for 0.5 hours. A mixture of methane and air was introduced into the reactor at 100 kPa. The conversion of methane was 91.46%, the selectivity of carbon monoxide and carbon dioxide were 96.47% and 3.53%, respectively.