Oxidative coupling of methane using carbon dioxide in an electric field over La–ZrO2 catalyst at low external temperature

Oxidative coupling of methane using carbon dioxide (CO2–OCM) as an oxidant was conducted over several La- and Zr-based catalysts in an electric field at low external temperature of 423 K. Higher catalytic activity was obtained than in a conventional catalytic reaction over 10 mol% lanthanum-doped zirconia (La–ZrO2) in the electric field. Although the catalytic activity for the CO2–OCM was low over the La–ZrO2 at 1173 K without the application of the electric field, the electric field promoted catalytic activity even at 423 K external temperature. We optimized the amount of doping-La in the La–ZrO2 system, and characterized the effect of doping-La with XRD measurement. From these examinations, 5 mol% La–ZrO2 catalyst showed the highest activity. High catalytic activity was provided by the synergistic effect of the La-cation, tetragonal-ZrO2, and the electric field.