Catalytic combustion is being widely studied as a means of controlling the NOx of combustors. However, the poor durability of palladium based catalysts hinders the development of catalytic combustors for the methane combustion reaction. The effects of the addition of platinum to PdO/Al2O3 on catalyst deactivation at 1073 K were studied using a fixed-bed flow reactor at atmospheric pressure. The adaptability of various deactivation equations to the data of methane combustion was investigated. The deactivation behavior of the catalysts could be expressed by an equation based on two kinds of deactivation species. The addition of Pt prolongs the lifetime of the PdO/Al2O3 catalyst by decreasing the initial activity. This is due not to the transformation of PdO to Pd-Pt but to the prevention of the growth of PdO and Pd-Pt particles during the reaction. (C) 2003 Elsevier B.V. All rights reserved.