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-ZrO ₂ catalyst showed the highest activity. High catalytic activity was provided by the synergistic effect of the La-cation, tetragonal-ZrO₂, and the electric field.