Effect of Cobalt Precursors on Properties of Co/CoAl<sub>2</sub>O<sub>4</sub> Catalysts Synthesized by Solvothermal Method
In the present study, different cobalt precursors, such as cobalt acetylacetonate (CoAA), cobalt acetate (CoAC), cobalt nitrate (CoN) and cobalt chloride (CoCL), were employed to synthesize the cobalt on cobalt-aluminate catalysts by the solvothermal process. The calcined samples were characterized by means of N2 physisorption, XRD, SEM/EDX, TEM and TPR. The CO hydrogenation under methanation condition was performed to measure the activity and product distribution. It revealed that the CoN sample exhibited the highest activity due to high reducibility and large crystallite size having fewer interactions. The similar trend was observed for the CoAC and CoAA samples. However, the CoCL sample had the lowest activity, but highest selectivity to C2-C4 products. This was likely attributed to the different form of cobalt oxide species obtained from CoCl2 as seen from XRD.