Catalytic Removal of Methane Over Cobalt Chromite (CoCr 2 O 4 ) Nanospinels for CNG Vehicles

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. Cobalt nitrate hexahydrate, chromium nitrate nonahydrate and ammonia solution (25%) were used as the starting materials. The obtained results show that the CoCr2O4 nanospinels were produced as single phase with an average diameter between 25-50 nm. Characterization studies by X- ray diffraction (XRD), N2 dsorption/desorption (BET), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), temperature program oxidation (TPO) and O2- temperature programmed desorption (O2-TPD) were carried out. The specific surface area (SBET) of the synthesized nanoparticles was measured using multiple point Brunauer– Emmett–Teller (BET) method.40 m2.g-1 was obtained for CoCr2O4 nanoparticles. The results revealed that cobalt chromite nanoparticles have significant capability for methane conversion at 435oC.