Modulation of Electronic States in Bimetallic-doped Nitrogen-Carbon Based Nanoparticles for Enhanced Oxygen Reduction Kinetics  

调制双金属掺杂氮碳基纳米颗粒的电子态以实现增强的氧还原动力学

作　　者：Chen Gong Chenyu Yang Wanlin Zhou Hui Su Qinghua Liu 龚宸;杨晨宇;周婉琳;苏徽;刘庆华(中国科学技术大学国家同步辐射实验室,合肥230029;湖南师范大学化学化工学院,长沙410081)

机构地区：[1]National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China [2]College of Chemistry and Chemical Engineering,Hunan Normal University,Changsha 410081,China

出　　处：《Chinese Journal of Chemical Physics》2024年第4期513-521,I0042-I0060,I0094,共29页化学物理学报（英文）

基　　金：supported by the Natural Science Foundation of Anhui Province(No.2208085J01 and No.2208085QA28).

摘　　要：Controlling the local electronic structure of active ingredients to improve the adsorption desorption characteristics of oxygen-containing intermediates over the electrochemical liquid-solid interfaces is a critical challenge in the field of oxygen reduction reaction(ORR)catalysis.Here,we offer a simple approach for modulating the electronic states of metal nanocrystals by bimetal co-doping into carbon-nitrogen substrate,allowing us to modulate the electronic structure of catalytic active centers.To test our strategy,we designed a typical bimetallic nanoparticle catalyst(Fe-Co NP/NC)to flexibly alter the reaction kinetics of ORR.Our results from synchrotron Xray absorption spectroscopy and X-ray photoelectron spectroscopy showed that the co-doping of iron and cobalt could optimize the intrinsic charge distribution of Fe-Co NP/NC catalyst,promoting the oxygen reduction kinetics and ultimately achieving remarkable ORR activity.Consequently,the carefully designed Fe-Co NP/NC exhibits an ultra-high kinetic current density at the operating voltage(71.94 mA/cm^(2)at 0.80 V),and the half-wave potential achieves 0.915 V,which is obviously better than that of the corresponding controls including Fe NP/NC,Co NP/NC.Our findings provide a unique perspective for optimizing the electronic structure of active centers to achieve higher ORR catalytic activity and faster kinetics.控制活性成分的局域电子结构以改善含氧中间体在电化学固液界面上的吸脱附特性是电催化氧还原反应催化领域的关键挑战.本文通过双金属共掺杂到碳氮基底中来调节金属纳米晶的电子态,从而实现催化活性中心电子结构的调制.首先,设计合成了一种典型的双金屆纳米颗粒催化剂(Fe-Co NP/NC),灵活地调控电催化氧还原反应的反应动力学.同步辐射X射线吸收谱和X射线光电子能谱结果表明,铁和钴物种的共掺杂可以优化Fe-CoNP/NC催化剂的本征电荷分布,促进氧还原动力学,并最终获得了显著的电催化氧还原反应电催化活性.Fe-Co NP/NC催化剂在0.80 V工作电压下表现出超高的动力学电流密度(71.94 mA/cm^(2)),半波电位达0.915 V,明显优于相应的单组分金属纳米颗粒样品.该研究发现为优化活性中心的电子结构以实现更优异的电催化氧还原反应催化活性和更快的反应动力学提供了一种通用的策略.

关 键 词：Oxygen reduction reaction Reaction kinetics Electronic state modulation CODOPING ELECTROCATALYSIS 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O643.36[理学—物理化学]