KINETICS AND MECHANISM OF THE CATALYTIC OXIDATION OF METHANE OVER LITHIUM-PROMOTED MAGNESIUM OXIDE.

Article abstract of DOI:10.1021/j100327a003

The kinetics of methane oxidation in CH//4O//2 mixtures over 7% lithium-promoted magnesium oxide has been investigated by dynamic mass spectrometry between 800 and 1100 K. At low pressures, rates become first order and half-order with respect to methane and oxygen, respectively, directly revealing the reversible dissociative chemisorption of O//2 on the catalyst. Otherwise, the complex rate law applicable over the entire range of pressures studied here can be accounted for by assuming competitive Langmuir adsorption of both reactants followed by chemical reaction of CH//4(g) with chemisorbed oxygen. The rate constant for methane oxidation exhibits Arrhenius behavior with E//a equals 86 kJ mol** minus **1.