Selective oxidation of methane to methanol in acetic acid solvent with Pd(OAc)2-p-benzoquinone-CO catalyst system

Selective aerobic oxidation of methane to methanol was carried out in an acetic acid solvent with Pd(OAc)2-p-benzoquinone-CO catalyst system; the effects of reaction temperature, time and solvent on the methane oxidation were investigated. The results showed that when the amount of Pd(OAc)2 is 100 μmol, the optimum amounts of p-benzoquinone and CO in the catalyst system are 1000 μmol and 0.4 MPa, respectively. With a feed of 2.5 MPa CH4 + 0.4 MPa O2 + 0.4 MPa N2, the optimal reaction conditions are 130°C, reaction time of 3 h, and volume ratio of CH3COOH to H2O being 4; under such conditions, the yield of methanol reaches 1650 μmol in a 250 mL reactor.