High entropy La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))O_(3)with tailored eg occupancy and transition metal-oxygen bond properties for oxygen reduction reaction  

作　　者：Wenyi Li Zhenxin Zhao Jinyu Zhao Yongzhen Wang Xiaomin Wang 

机构地区：[1]College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China [2]Shanxi Joint Laboratory of Coal based Solid Waste Resource Utilization and Green Ecological Development,Taiyuan 030024,China

出　　处：《Journal of Materials Science & Technology》2024年第27期236-246,共11页材料科学技术(英文版)

基　　金：supported by the Key R&D Program of Shanxi Province(Nos.202102030201006 and 202202070301016);the National Natural Science Foundation of China(No.52072256);the Shanxi Science and Technology Major Project(No.20201101016);the Natural Science Foundation of Shanxi Province(Nos.20210302124105 and 20210302124308);the Centralized Guided Local Science and Technology Development Funds Project(No.YDZJSX2021B005);the Shanxi Provincial Science and Technology Innovation Base Construction Project(No.YDZJSX2022B003).

摘　　要：Forming high entropy oxide provides a feasible approach to finding a balance among moderate eg oc-cupancy,high transition metal-oxygen(TM-O)covalency,and lattice energy,which is essential to en-sure efficient and durable oxygen reduction reaction(ORR)process for perovskite lanthanide-transition metal oxides(LaTMO_(3)).However,due to the compositional complexity,clarifying the relevance among the high entropy components,eg occupancy,TM-O properties,and ORR performance still remains a chal-lenge.Herein,adopting the B site entropy-driven strategy,a series of LaTMO_(3)(TM=Cr,Mn,Fe,Co,Ni)with tunable eg occupancy and TM-O bond properties are synthesized,and the correlations between high entropy elements,eg occupancy,TM-O properties,and ORR performances are revealed quantitively based on the crystal field theory and the Phillips-Van Vechten-Levine(P-V-L)valence bond theory.High en-tropy La(Cr_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))O_(3)delivers a low overpotential of 493 mV(vs.503 mV for LaMnO_(3))and a minuscule decline by only 1.7%(vs.4.4%for LaMnO_(3))in half wave potential after 10,000 cycles,which can be associated with the tailored eg occupancy(1.06)and the significant enhancement in both TM-O covalency(4%)and lattice energy(691.75 kJ mol^(-1)).This work not only demonstrates the prospects of high entropy LaTMO_(3)in the ORR field but also provides a new perspective for the quantitative analysis of the structure-activity relationship for high entropy oxide ORR catalysts.

关 键 词：High entropy oxide e_(g)occupancy TM-O covalency TM-O lattice energy LaTMO_(3) Oxygen reduction reaction 

分 类 号：O61[理学—无机化学]