Catalytic Removal of Methane Over Cobalt Chromite (CoCr2O4) Nanospinels for CNG Vehicles

Abstract

<em>Cobalt chromite (CoCr₂O₄) with normal spinel structure, shows catalytic activity for oxidation of unburned methane in the natural gas vehilcles (NGV). In this study, CoCr₂O₄ nanoparticles were synthesized through a conventional co-precipitation technique and investigated for the catalytic combustion of methane.</em><em> Cobalt nitrate hexahydrate, chromium nitrate nonahydrate and ammonia solution (25%) were used as the starting materials</em><em>. </em><em>The obtained results show that the </em><em>CoCr₂O₄ nanospinels were produced as single phase with an average diameter between 25-50 nm.</em><em>Characterization studies by X- ray diffraction (XRD), </em><em>N₂ adsorption/desorption</em><em>(BET)</em><em>, </em><em>field emission scanning electron microscopy</em><em> (FESEM), </em><em>transmission electron microscopy</em><em> (TEM</em><em>), </em><em>temperature program oxidation</em><em> (TPO) and </em><em>O₂- temperature programmed desorption</em><em> (O₂-TPD) were carried out.</em><em>The specific surface area (S_BET) of the </em><em>synthesized nanoparticles was measured using multiple point Brunauer–Emmett–Teller (BET) method.40 m².g^-1was obtained for CoCr₂O₄ nanoparticles. </em><em>The results revealed that cobalt chromite nanoparticles have significant capability for methane conversion at 435</em><em>^o</em><em>C</em><em>. </em>