Research On Metal Ions Doped Perovskite Oxides As Oxygen Catalysts

In today's society,energy is increasingly inseparable.In order to use energy efficiently,the catalyst plays an irreplaceable role.Among many catalysts,oxygen catalyst can be said to be the leader because of the application of many aspects such as fuel cells,electrolyzed water,and metal air batteries.The oxygen catalyst is mainly divided into an oxygen evolution catalyst and an oxygen reduction catalyst.The oxygen evolution catalyst is represented by cerium oxide?IrO₂?,and the oxygen reduction catalyst is represented by platinum carbon?Pt/C?.These catalysts have high activity in each field,but are also faced with the characteristics of high price and poor stability.Therefore,the development of new non-precious metal catalysts has attracted everyone's attention.The perovskite oxides use in this paper have attracted much attention because of their special structures and remarkable catalytic activities.This paper mainly studies metal ion doped perovskite oxide catalysts for oxygen catalytic reactions.For the oxygen evolution catalytic reaction,B-site doping of BaCo_0.5Fe_0.5O_3-?with different amounts of Zr and Y ions was carried out.It was found that when the doping amount was 0.1,the activity of the catalyst was the highest.Ba?CoFe?_0.4?ZrY?_0.1O_3-?catalyst has good oxygen evolution activity when tested on a rotating disk.The potential versus reversible hydrogen electrode is only 1.59V at current density of 10 mA cm^-1,higher than the commercial catalyst IrO₂ and the benchmark Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-?,the long-term catalytic stability is also better.After assembled into electrolytic tank,the prepared catalyst still has high stability and excellent battery performance.In order to understand the properties of materials more deeply,this paper also uses iodine titration and Mossbauer spectroscopy to analyze and explain the decisive role that Zr,Y ions played.For the oxygen reduction reaction,the hybrid oxygen reduction catalyst Pr_xBa_1-xCo_0.8Zr_0.1Y_0.1O_3-?was prepared by doping Pr ion into BaCo_0.8Zr_0.1Y_0.1O_3-?,compared with the single-phase catalyst and the standard perovskite oxide Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-?,the activity is higher and the reaction is more sufficient.Through a series of doping studies,we find that as the doping amount of Pr ions increases,the oxygen reduction activity of the catalyst also increases,in order to better analyze the influence of doping amounts of the Pr ion to the catalyst activity and catalytic law,this paper makes the infrared phase spectroscopy and iodine titration tests on the composite phase catalyst and surface oxygen behavior,explains the reason why the composite phase catalyst has higher activity and has a specific variation law,and also provides a synthetic ideas of high activity catalyst.The work in this paper provides a new idea for the application of perovskite-type oxide catalysts in electrolyzed water and metal-air batteries,and provides a new and feasible solution for designing more efficient catalysts.At the same time,it should also be actively explored the new idea to further improve the catalytic activity of oxygen precipitation and oxygen reduction of perovskite oxide catalysts has become a new low-cost,high-performance catalyst.