Characterization of the Structure Feature of Bimetallic Fe-Ni Catalysts

Production of hydrogen gas from biomass gasification usually comes with several problems such as the existence of unacceptable level of tars and also ineffectiveness of the catalysts performance due to coke deposition. In order to eliminate most of the inconvenience encountered, new types of catalyst have been developed. In this study, bimetallic Fe and Ni supported on zeolite beta have been prepared by incipient wetness impregnation method with different calcination temperatures (500-700ºC). The interaction of active metals and support on the structure, metals transition and reduction were characterized by physicochemical techniques such as BET, XRD, FESEM-EDX and TPR. The results showed that the active metals incorporated with zeolite beta in bimetallic systems exhibit a strong Fe-Ni/BEA interaction which stabilizes Fe3+ and Ni2+ ions in the lattice. Reducibility of nickel increased in the presence of Fe, which was confirmed by the combination of active metals reduction peaks attributed to weak interaction with the support, Fe2O3 to Fe3O4 to FeO and strong interaction with the support between FeAl2O4 and NiAl2O4. Bimetallic catalysts have a bigger surface area with increasing calcination temperatures which is closely related to high activity in the gasification reaction. It was found that different calcination temperatures give a significant effect to the precursor whereby FeNi/BEA (600ºC) showed better physicochemical properties than other samples with high reducibility even though it has low surface area.