Non-noble Metal Catalysts For Oxygen Evolution Reaction And Oxygen Reduction Reaction

Electrocatalysts for the oxygen evolution reaction?OER?and oxygen reduction reaction?ORR?are core materials in many renewable energy technologies such as fuel cells,metal-air batteries,and water splitting devices.However,the high cost of the catalysts such as platinum and iridium oxide severely hinders the commercial development of these devices.So,it is important to design and synthesis non-precious metal with high efficiency and stability to solve the issues.Nanoporous carbons stand out from the many candidates for ORR and OER catalysts due to their low costs,high electrical conductivities,and good stabilities.At present,using metal organic skeleton materials?MOFs?as a precursor is a common method of preparation porous carbon materials.With characteristics of high specific surface area,tunable porosity and functionalization,the MOF-derived materials could inherit the advantages of these and used as a promising catalyst.Based on the above discussion,this paper carried out the preparation of non-noble metal catalyst used for ORR and OER.Firstly,a series of N,S co-doped porous carbons?NSCs?possessing good ORR performance were prepared with a dual-ligand metal-organic framework?MOF?as a carbon precursor.The interconnected porous structure coated with graphene layers,high surface area,N,S co-doping and high graphitization N dopant contribute to the enhanced catalytic performance of ORR.The electrocatalyst studies indicated that the obtained materials have considerable ORR activity in both alkaline and acidic media.Secondly,by using an easy method for producing effective bifunctional oxygen reduction and oxygen evolution catalysts through the design of bimetallic metal organic framework precursor.The ratio of Zn and Co was optimized to search the critical factors affecting the catalysis of the ORR and OER.We found that for ORR catalysis,both Co/Co9S8 species and heteroatom-doped porous carbons played important roles.In contrast,the Co/Co9S8 species play more important role in OER catalysis.The optimized catalyst NSC-1-5 showed excellent performance.Thirdly,we prepared a porous carbon incorporated cobalt boride with a metal organic framework as precursor and the OER catalytic activity was greatly enhanced due to the high catalytic active Co-B and good conductivity increased by carbons.It produces an excellent catalytic activity when used as OER catalyst in 1 M KOH solution.Finally,we synthesis a dimension Co2Mo3O8-MoO2@C nanorods by using MoO3@ZIF-67 composites as precursor.The Co2Mo3O8-MoO2@C materials exhibit excellent merits toward OER in basic solution with an overpotential of 320 mV to deliver a current density of 10 mA cm^-2.This material possesses an attractive OER performance due to the active Co₂Mo₃O₈ and MoO₂ species in the catalyst and the unique structure.