Methane activation over unsupported and La2O3-supported copper and nickel catalysts

Methane was pulsed over pure CuO and NiO as well as Cu/La2O3 and Ni/La2O3 catalysts at 600 degrees C. Results indicate that the mechanisms for methane activation over copper and nickel are quite different. Over CuO, methane is converted to CO2 and H2O, most likely via the combustion mechanism; whereas metallic copper does not activate methane. Over NiO in the presence of metallic nickel sites, methane activation follows the pyrolysis mechanism to give CO, CO2, H-2 and H2O. Similar results were obtained over the Cu/La2O3 and Ni/La2O3 catalysts. XRD investigations indicate that copper and nickel existed as CuLa2O4 and LaNiO3 respectively in the La2O3-supported catalysts. The effect of La2O3 on the activation of methane is discussed.