2743.     PRETTRE, M., EICHNER, C., AND PERRIN, M.  Catalytic Oxidation of Methane to Carbon Monoxide and Hydrogen.  Trans. Faraday Soc., vol. 42, 1946, pp. 335-340; Chem. Abs., vol. 41, 1947, p. 2225.

        Controlled catalytic oxidation of CH₄ to CO and H₂ usually is represented by the equation:  CH₄+1/2 O₂=CO+2H₂.  Experiment shows, however, that in practice, at temperatures up to 1,500° K, conversion yields corresponding with the values of the equilibrium constants for the above reaction are never obtained.  The oxidation results from an initial reaction of complete combustion of part of the CH₄, CH₄+20₂=CO₂+2H₂O, which consumes all the O₂.  The residual CH₄, amounting to approximately ¾ of that originally taken, then reduces the water vapor and CO₂:CH₄+H₂O=CO+3H₂ and CH₄+CO₂=2CO+2H₂.  Since these equilibria do not give good yields in the absence of a large excess of oxidants, except at fairly high temperatures, it is necessary to effect catalysis at above 850°, or even 900°, to obtain a product containing not more than traces of CH₄.  (See abs. 779.)