We examined oxidative coupling of methane (OCM) over various Ce-W-O catalysts at 423 K in an electric field. Ce2 (WO4)3/CeO2 catalyst showed high OCM activity. In a periodic operation test over Ce2 (WO4)3/CeO2 catalyst, C 2 selectivity exceeded 60% during three redox cycles. However, Ce2 (WO4)3/CeO2 catalyst without the electric field showed low activity, even at 1073 K: CH 4 Conv., 6.0%; C 2 Sel., 2.1%. A synergetic effect between the Ce2 (WO4)3 structure and electric field created the reactive oxygen species for selective oxidation of methane. Results of XAFS, in-situ Raman and periodic operation tests demonstrated that OCM occurred as the lattice oxygen in Ce2 (WO4)3 (short W-O bonds in distorted WO 4 unit) was consumed. The consumed oxygen was reproduced by a redox mechanism in the electric field.
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