The Direct Partial Oxidation of Methane to Dimethyl Ether over Pt/Y2 O3 Catalysts Using an NO/O2 Shuttle.

Using a mixture of NO + O2 as the oxidant enabled the direct selective oxidation of methane to dimethyl ether (DME) over Pt/Y2 O3 . The reaction was carried out in a fixed bed reactor at 0.1 MPa over a temperature range of 275-375 °C. During the activity tests, the only carbon-containing products were DME and CO2 . The DME productivity (μmol gcat -1  h-1 ) was comparable to oxygenate productivities reported in the literature for strong oxidants (N2 O, H2 O2 , O3 ). The NO + O2 mixture formed NO2 , which acted as the oxygen atom carrier for the ultimate oxidant O2 . During the methane partial oxidation reaction, NO and NO2 were not reduced to N2 . In situ FTIR showed the formation of surface nitrate species, which are considered to be key intermediate species for the selective oxidation.