Effects of oxidation pretreatment temperature on Kovar used as CO2 reforming catalyst

The effect of oxidation pretreatment temperature (500–1000°C) on the catalytic activity of Kovar applied on hydrocarbon CO2 reforming was examined. Catalytic performance evaluation using tetradecane at 800°C with 70 μmol/s CO2 revealed 700 and 1000°C as the best pre-oxidation temperature in producing CO and H2, respectively. XRD and SEM-EDX analyses showed that a separate metal oxide layer composed of iron oxide (Fe2O3 and F3O4), nickel, cobalt, and possibly their respective oxides started to form when oxidation was conducted at 700°C or higher. The presence of iron enhanced the stability of nickel in the structure while the compact structure of Fe3O4 resulted into the formation of a thick and rigid metal oxide layer on the surface of the Kovar tube. The strong physical bond between the metal oxide layer and Kovar tube provided the catalyst good mechanical strength and consequently good catalytic activity.