Microwave heating was applied in the oxidative coupling of methane to higher hydrocarbons over alumina supported La2O3/CeO2 catalysts. It was found that microwave heating had a dramatic effect on the reaction when methane was converted into C-2 hydrocarbons in the absence of oxygen, with products produced at measured temperatures about 250 degreesC lower than those observed with conventional heating. It was shown that the reaction in the absence of oxygen occurred primarily in the gas phase and it was the localised heating of the methane that was responsible for the increased reaction rate. However, it was observed that microwave heating did not produce significant "special microwave effects" which affected the product species formed when the oxidative coupling reaction occurred in the presence of oxygen. (C) 2003 Elsevier Science B.V. All rights reserved.