Study On The Fabrication And Performance Of Ni_0.5Cu_0.5Fe₂O₄-BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ Reforming Catalytic Layer

Solid oxide fuel cell（SOFC）is a electrochemical device that convert chemical energy of fossil fuel into electricity.Metal-supported solid oxide fuel cell（MS-SOFC）has the advantages that traditional SOFC does not have in terms of cost,manufacturing,durability,and so on.But most researches of MS-SOFC use hydrogen as fuel,and the hydrogen’s cost of preparation,storage,and transportation is very high,virtually increasing the cost of SOFC.Direct use of hydrocarbon as fuel does not present these problems,but the direct use of hydrocarbon fuels can cause anode carbon deposition problem.Adding a reforming layer to the electrode structure to reform the hydrocarbon fuel on-cell can avoid the direct contact of the hydrocarbon fuel with the Ni-based anode,thereby achieving the purpose of suppressing carbon deposition.In this paper,NiCuFe（NCF）alloy is used as reforming catalyst and BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ（BZCYYb）is used for modification.The NCF-BZCYYb reforming catalyst material is prepared and optimized as a reforming catalyst.We aslo studied the long-term stability of MS-SOFC when NCF-BZCYYb was uesd as reforming layer.Considering NCF and BZCYYb has different effects on the methane reforming reaction,their mass ratio in the composite will directly affect its catalytic performance and carbon deposition resistance of the reformer layer.In this paper,NCF-BZCYYb catalysts with different composition ratios were prepared first.The optimum composition was optimized by studying the conversion rate of methane fuel,the composition of reforming products and the carbon deposition behavior.The NCF-BZCYYb was then used as the reforming layer in the MS-SOFC cell.Using methane as fuel,its effect on cell discharge performance and long-term stability was investigated.Based on the experimental results,the following main conclusions are drawn:（1）With the increase of NCFO,the conversion efficiency of CH₄ and the selectivity of CO increase;the ratio change of NCFO and BZCYYb has little effect on the carbon deposition activity,but it has a great effect on the morphology of carbon deposition after catalytic.The effect of S/C ratio on the catalytic reforming reaction of methane was studied by changing the water vapor content.The result showed that within a certain range,as the S/C ratio increased,the conversion efficiency of CH₄ increased and the CO selectivity decreased.（2）The optimum reforming catalyst was screen printed in a metal-supported SOFC to investigate the electrochemical performance of single cell with and without catalyst reforming layer in CH₄-3 mol.%H₂O and H₂-3 mol.%H₂O.The long-term stability of single cell with and without catalyst reforming layer in CH₄-3 mol.%H₂O were studied,too.The results show that the electrochemical performance in CH₄-3 mol.%H₂O and H₂-3mol.%H₂O of single cells with or without reforming catalytic layer is similar,which means there are amount of H₂ after reforming of CH₄.There is no obvious effect on the electrochemical performance of CH₄-3 mol.%H₂O and H₂-3 mol.%H₂O in single cell with catalytic reforming layer.The cell with a reforming catalyst layer started to degrate after 700min of running,while the cell without refoming layer completely failed after100min running.Therefore,adding a catalytic reforming layer improve the long-term stability of the cell in hydrocarbon fuel.