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

摘要

Methane conversion was conducted over various perovskite oxide catalysts at 423 K using carbon dioxide as an oxidant in an electric field. La0.7Ca0.3AlO3-delta catalyst showed high CO2-OCM activity. The highest CO2-OCM activity, C-2 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 (H-2 + 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 C-2 hydrocarbon formation.