Selective oxidation of methane to methanol and formaldehyde with nitrous oxide in a dielectric-barrier discharge - Plasma reactor

The partial oxidation of CH4 with N2O in Ar has been investigated at atmosp heric pressure in a dielectric-barrier (silent) discharge plasma induced by low input power in a range from 0.27 to 7.71 Wh(Ncm(3))(-l). In an Ar stre am, about 10% of the combined yield of CH3OH and HCHO and 40% of the select ivity to these products were achieved, with CO being the other major produc t. Low power favored selectivities to unstable partial oxidized products an d supressed further decomposition to carbon oxides and carbonaceous deposit s on the electrode surface. Kinetic and spectroscopic observations indicate d that Ar carrier gas played an important role in the highly selective oxid ation of CH4 to CH3OH and HCHO via energy transfer from excited-state Ar sp ecies to the reactant molecules under the mild conditions examined.