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Structural, catalytic and magnetic properties of Cu <inf>1-X</inf> Co <inf>X</inf> Fe <inf>2</inf> O <inf>4</inf>

Abstract:

Copper substituted cobalt ferrite Cu 1-X Co X Fe 2 O 4 (0 x 1) have been synthesized using sol-gel auto combustion method with citric acid as fuel. Structural identification, magnetic and catalytic properties were investigated using thermogravimetric and differential thermal analysis, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry and their application in the selective catalytic reduction of NOx were studied. Analysis of structural properties reveals that all samples have cubic spinel structure. Room temperature magnetic hysteresis measurements as a function of magnetic field infer that the magnetic properties decrease with Cu 2+ doping which may be due to the difference of the magnetic moment of Cu 2+ and Co 2+ ions. The higher activity of the samples in NO selective reduction to N 2 occurs at 350 °C, reaching a maximum of 38% NO conversion and 95% of selective conversion to N 2 . The compositions containing both Cu 2+ and Co 2+ ions are more active to the products selectivity to N 2 , suggesting a synergistic effect on the active surface of ferrite and the effect of Co 2+ is more pronounced than Cu 2+ towards NO conversion. © 2012 Elsevier B.V.