The Ni-based Catalyst Performance Study For Methane Steam Reforming In Solid Oxide Fuel Cell System

Methane steam reforming is the most mature hydrogen production method in industrialization.At present,the coupling application of methane steam reforming and solid oxide fuel cell?SOFC?system has given the reforming technology more important significance,which has attracted wide attention of researchers.Ni-Al₂O₃ catalyst is the most widely used non-precious metal reforming catalyst,but the Ni-based catalyst has poor carbon deposition resistance,and there are also problems such as mismatch when used in SOFC system.Therefore,Ni-Al₂O₃ catalysts with different Ni impregnation amounts and Ni-Al₂O₃ catalysts with different precursor calcination temperatures were prepared by traditional impregnation method.The material characterization showed that the Ni element on the catalyst surface was uniformly distributed and the microscopic pore structure was uniform and it has a large surface area.The catalyst preparation process and reaction conditions were investigated.The Ni impregnation amount was 10%,the calcination temperature was 600°C,the reaction temperature was 750°C,the catalyst performance was best when the water-carbon ratio was 2:1,and the catalyst optimum performance of CH₄ conversion is 79.2%,and the CO selectivity is 80.91%,the H₂ yield is 58.86%.In order to further improve the catalytic performance and carbon deposition resistance of the catalyst,a 10%Ni-X-Al₂O₃ catalyst containing different promoters and promoters impregnation amounts was prepared?X=Co/Mg/Zn/Cu/K?.The 10%Ni-5%Mg-Al₂O₃ catalyst exhibits excellent performance similar to that of noble metal catalysis.The methane conversion rate can reach 85.25%,the hydrogen yield reaches62.29%,and no carbon deposition occurs during the reaction.The discharge performance and impedance of the battery were tested under different fuel gases.When the battery was fueled by reformed gas and hydrogen,the maximum power density was 0.17 W·cm^-2 and0.24 W·cm^-2,which were better than those of methane fuel gas;the impedances are 0.8?·cm² and 0.85?·cm²,respectively,which are better than 2.0?·cm² in methane fuel gas,indicating that methane steam reforming can combine with SOFC system.Finally,the paper proposes a scheme,which integrates the methane steam reforming unit and the SOFC system,and uses the waste heat for secondary utilization while generating electricity,improving the comprehensive utilization of energy and achieving the goal of high efficiency and environmental protection.The solution also provides a viable design approach for future applications of small methane reformers for commercial SOFC systems.