The Direct Partial Oxidation of Methane to Dimethyl Ether over Pt/Y₂O₃Catalysts Using an NO/O₂Shuttle

Abstract

Using a mixture of NO + O2 as the oxidant enabled the direct selective oxidation of methane to dimethyl ether (DME) over Pt/Y2O3. 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 (N2O, H2O2, 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.

Study of the Methanol Conversion into Dimethyl Ether Obtained in the Process of Biomimetic Methane Monooxidation by Hydrogen Peroxide

“…A comparative analysis of recent works [12,13] (refer to the introduction) demonstrates that the proposed method offers several advantages. Specifically, the direct conversion of methane into methanol and dimethyl ether occurs in a single reactor using a biomimetic catalyst and "green oxidizer" H2O2 without generating any harmful by-products, which is the relevance of this work.…”

“…There are works in which the direct conversion of methane to DME on Pt/Y2O3 and Pd/SiO2, Pd/ZrO2, and Pd/SiZrO2 catalysts was carried out using a mixture of NO and O2 as an oxidant. During the reaction, together with DME, a significant amount of CO2 is obtained, and the gases NO and NO2 participating [12,13] in the reaction are not reduced to N2, which is the main disadvantage of these works.…”