Selective Oxidative Activation of Methane

Methane oxidation to syngas has recently been presented as the most interesting method for methane valorization. In fact, the catalytic partial oxidation (CPO) of methane to syngas has widely been studied as a potential alternative to methane steam reforming since it is mildly exothermic and a H2/CO ratio of 2 is obtained in the ideal reaction CH4 -I- 1/2O2 CO - - 2H2 (AH gg = -36kJ/mol ), which is comparable to Fischer-Tropsch synthesis.This has been reviewed recently.  

However, the selectivities towards H2 and CO can be strongly influenced by the simultaneous occurrence of methane total combustion and/or secondary oxidation reactions of CO and H2, such as the formation of water and carbon dioxide, which can be favored at high reaction temperatures. 

Ni-based catalysts were initially reported, with further investigations of different group VIII metals (Rh, Pt, Pd, Ir, Ni, Fe, Co, Re, and Ru). The 

Since catalytic partial oxidation seems to be appropriate for Fischer-Tropsch syntheses, it has also been proposed that the heat required for methane steam reforming could be balanced by the exothermic oxidation of methane. In this way, a quasi-homogeneous, one-dimensional model has been developed from the study of partial oxidation of methane in the presence of steam over a 5% Ru-supported on y-Al203, which according to authors can help in pilot reactor design, materials, and further scale-up. 

On the other hand, it has been reported that a better OCM 5deld, which is 23% (70% C2-selectivity at 32% methane conversion, using a CH4/air molar ratio of 1), is obtained using air as the oxidant instead of oxygen (16% yield, with 80% 

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