Low-temperature oxidative coupling of methane in an electric field using carbon dioxide over Ca-doped LaAlO₃ perovskite oxide catalysts

Methane conversion was conducted over various perovskite oxide catalysts at 423 K using carbon dioxide as an oxidant in an electric field. La_0.7Ca_0.3AlO_3-δ catalyst showed high CO₂-OCM activity. The highest CO₂-OCM activity, C₂ yield of 7.4%, was obtained even at 348 K, that value was higher than those of other earlier reports. Dry reforming of methane to produce syngas (H₂ + CO) proceeded simultaneously, and no other byproduct was observed. Results of in-situ IR, XRD and TG measurements demonstrated that CO₂ adsorption on the catalyst surface and formation of La₂O₂CO₃ intermediate are important for progress of the CO₂-OCM reaction, even at low temperature in an electric field. Ca atom incorporated in LaAlO₃ perovskite played an important role in C₂ hydrocarbon formation.