Synthesis of porous NiFe2O4 microparticles and its catalytic properties for methane combustion

In this paper, we report the obtention of agglomerate porous NiFe2O4 microparticles type-spinel with uniform size of 1–2 μm by the oxalic acid co-precipitation method. The structure, morphology and surface of microparticles as-synthesized were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), respectively. Fixed bed reactor test confirmed that the NiFe2O4 microparticles exhibit a good catalytic activity for methane combustion with the methane light-off temperature below 350 °C. XPS spectrum revealed that the excellent catalytic activity may be attributed to the surface oxygen vacancies arising from the peculiar inverse spinel structure with octahedral (Oh) site occupied by Fe2+ and Ni2+ cations.