Preparation And Electrochemical Performance Of Cu-CeO₂ Based Fuel Electrode For High Temperature Solid Oxide Reversible

Reversible solid oxide fuel cells is a kind of new device that is environmentally friendly and with high conversion efficiency.They but can change fule chemical energy into electrical energy on the SOFC?solid oxide fuel cells?mode also can change electrical energy into chemical energy when there is enough electrical energes with the mode of SOEC?Solid Oxide Electrolyte Cells?.They can be operated very conveniently between the energes changing.As the same time,this kind of device has a lot of merits just like the modularization structure is easier,less land occupatation and without pollutants of noise.For these reasons,the development of RSOFC is very important in the environments of the less of fossil resource and the more serious of pollutions.In this paper we studied a new type of metal ceramic fuel RSOFC materials.The traditional electrode is a composite of Ni and YSZ?Y2O3 stabilized ZrO₂?,However,when using CO and hydrocarbon fuel as fule the Ni-YSZ fuel electrodes suffer from sulfur poisoning and carbon coking which is another major issue during the long term operation of the reversible SOFCs,leading to degradation of the cell in the long-term running.So found a new electrode materials that can normal work in different atmosphere for RSOFC is currently needed research of work.In this paper,Using Cu as a protective layer on the Ni-YSZ composite electrode because it has good conductivity and resistance to carbon coking.As the same time we all know that CeO₂-based electrode has good catalytic on hydrocarbon fuel,higher oxygen vacancies and high Ionic conductivity.So in this experiment we studied the CeO₂-based electrode by doping Fe,Mn elements.We prepared Cu-Ce_0.9Fe_0.1O_2-? ? CuCe0.9Mn0.1O₂-? ? Cu-Ce0.6Mn0.3Fe0.1O₂-? three kinds of fuel electrodes to improve oxygen storage,release and electrochemical properties of CeO₂-based electrode.The electrochemical performance experiments were measured by using Arbin fuel cell testing system.When on the model of SOFC,The maximal power densities can reach up to 177mW/cm2 321mW/cm2,749.3 mW/cm2 at 800 oC in H2 atmosphere respectively.From this we know that Ce0.6Mn0.3Fe0.1O₂-??CMF?electrode exhibit a good performance.And the electrode of CMF still has the highest power densities 691.9 m W/cm2 when the fuel switch to CO fule,combined with the activation energy testing of Cu-CMF electrode in H2?0.70 eV?and CO?0.77 eV?,It is very closed.By comparing CeFe,CeMn and CFM there electrode materials,we conclude that CMF is a better suited to different types of fuel atmosphere.When the reversible SOCs are operated in solid oxide electrolysis cell mode,the current densities can reach up to 2.204 A/cm2?1.466A/cm2?0.95 A/cm2 at 800 oC for CuCe0.6Mn0.3Fe0.1O₂-? ?Cu-Ce_0.9Fe_0.1O_2-? ?Cu-Ce0.9Mn0.1O₂-? electrode materials respectively for pure CO₂ reduction.From this result we know that CFM is still the best electrode to reduce CO₂.The polarization resistance under the same conditions of the electrolysis cell for pure CO₂ reduction verified the result,At 800 oC the CFM has the minimal value of 0.151?cm2 at 1.6 V,The durability of the fuel cell in H2 and CO for as long as 200 h indicates the CFM electrode has remarkable stability confirmed that CFM is a potential development RSOFC fuel electrode material.