Application Of Perovskite Materials In Solid Oxide Fuel Cells And Electrocatalytic Nitrogen Reduction Energy Devices

With the continuous development and progress of modern society,the environment and energy resources on which mankind depends for survival are also facing a huge crisis.Therefore,the development of environmentally friendly and sustainable energy conversion devices has become an urgent theme in today's society.Perovskite-type composite oxide is a new type of material with unique physical and chemical properties.In perovskite materials,the A site is generally a rare earth or alkaline earth element ion,and the B site is a transition element ion.Both the A site and the B site can be partially replaced by other metal ions with similar radii to keep their crystal structure basically unchanged.Perovskite materials are ideal materials for studying the surface of catalysts,that is,their catalytic performance.We designed the applications of perovskite materials in proton conductor solid oxide fuel cells and electrocatalytic nitrogen reduction energy conversion devices,and discussed their effects.The effect of oxygen vacancy riched perovskite on the properties of two energy conversion devices is studied as follows:1.Testing the electrochemical performance of BaZr_0.8Y_0.2O_3-?(BZY20)materials requires sintering dense BZY20 particles.In fuel cell testing,Pt is often used as a conductive electrode and since Pt is considered an inert material,the potential reaction between Pt and BZY20 is usually ignored.However,some studies have shown that Pt can react with another proton conductor,Ba Ce O₃.The formation of the secondary phase at high temperature indicates that Pt is not completely inert to the proton conductor oxide at high temperature.Therefore,we predict that a potential reaction may occur between Pt and BZY20.So far,we have not done anything in this regard.Confirmed conclusion.Our research found that Pt can diffuse into the crystal lattice of the BZY20 material at high temperatures,further affecting the alkalinity,water and capacity of the material itself,and improving the proton conduction.2.The catalytic performance of the catalyst in the electrochemical nitrogen reduction reaction is mainly related to the oxygen vacancy,which not only changes the electronic structure around the metal oxide,but also serves as a reaction site for3.adsorbing reactants,thereby reducing the activation energy barrier.It is well known that perovskite oxides usually contain oxygen vacancies and their unique electronic structure,indicating that they can act as an excellent catalyst and be applied in the field of electrochemistry.For example,doped La Fe O_3-?(LFO)is widely used as a catalyst in the field of electrochemical catalysis,such as photocatalysis,solid oxide fuel cells,etc.,but they are rarely used in NRR.Considering the tolerance of NH₃to harsh conditions,it is necessary to study whether highly doped perovskites(containing a large amount of oxygen vacancies)can perform a good NRR reaction at room temperature,that is,to explore whether oxygen vacancies can be fully utilized.NRR.In addition,NRR may occur at the sites of Fe ions and oxygen vacancies in the La Fe O₃matrix,but the different effects between Fe and oxygen vacancies in NRR are still unclear.In order to answer these questions,we reported that a Sr-doped LFO(La_0.5Sr_0.5Fe O_3-?,LSFO)catalyst enhances the NRR of NH₃synthesis,aiming to reveal the effect of oxygen vacancies on the performance of NRR.On this basis,using density functional theory(DFT)theoretical calculations,the role of oxygen vacancies in NRR is discussed from an atomic point of view.