Potential intermediate in CH 4-assisted reduction of nitric oxide: the reactions of methyl nitrite on oxidized Mo(1 1 0)

Abstract

The reactions of methyl nitrite (CH 3ONO) on O-covered Mo(1 1 0) were studied in order to determine whether methyl nitrite is a possible intermediate in CH 4-assisted reduction of NO. Methyl nitrite decomposes to NO and methoxy (CH 3O ads) upon adsorption at low temperature. Most NO is evolved directly into the gas phase at 110 K, although a small fraction is trapped on the surface and is identified using infrared spectroscopy. Methoxy remains on the surface until ∼600 K, at which point it decomposes to gas phase • CH 3 and adsorbed oxygen. Hence, the overall reaction is the reverse of the • CH 3+ NO reaction. However, no reduction products (N 2 or N 2O) are evolved. The absence of reduction may be due to the fact that all high coordination sites are occupied on the O-covered surface or to the low coverage of NO. These results are discussed in the context of • CH 3-assisted NO reduction.