SYNTHESIS AND CHARACTERIZATION OF MAGNETITE NANOCATALYST VIA SOL GEL-HYDROTHERMAL METHOD

Magnetite (Fe3O4) is known as a catalyst for ammonia synthesis. However, to synthesis magnetite nanocatalyst still remains as a challenge. Therefore, a hybrid method namely sol gel-hydrothermal was introduced as one of the synthesis methods. The synthesis was done by pressurizing Fe (III) gel in an autoclave. The effects of hydrothermal temperature from 28-160oC on the physicochemical properties of as-prepared magnetite nanocatalysts were studied using XRD, FESEM, TPR and VSM. Highly crystalline, single phase and sponge-like shape of magnetite nanoparticles were obtained when the synthesis temperature was elevated to 160oC as depicted by XRD and FESEM. Based on TPR profiles, the maxima reduction peak appeared at temperature in the range of 500-600oC was assigned to the reduction of Fe3O4 to FeO. Further reduction of FeO to Fe was occurred at temperature in the range of 780-920oC as represented by a broad peak. VSM result showed the magnetization saturation, Ms of this catalyst was 55.69 emu/g.