Chinese Journal of Applied Chemistry ›› 2020, Vol. 37 ›› Issue (8): 939-951.DOI: 10.11944/j.issn.1000-0518.2020.08.200044

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Improving the Electrocatalytic Activity of La2NiO4+δ Cathode by Surface Modification with Conformal Heterojunction

WEI Zhenyea,b, MENG Junlinga,b*, WANG Haoconga,b, ZHANG Wenwena,b, LIU Xiaojuana,b*, MENG Jiana,b   

  1. aState Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China;
    bUniversity of Science and Technology of China,Hefei 230026,China
  • Received:2020-02-17 Published:2020-08-01 Online:2020-08-07
  • Contact: LIU Xiaojuan, professor; Tel:0431-85262415; Fax:0431-85698041; E-mail:lxjuan@ciac.ac.cn; Research Interests:solid oxide fuel cell; MENG Junling, assistant professor; Tel:0431-85262541; E-mail:mengjunling@ciac.ac.cn; Research Interests:solid oxide fuel cell
  • Supported by:
    National Natural Science Foundation of China(No.21571174, No.21590794), and the Provincial Natural Science Foundation of Jilin(No.20190201106JC)

Abstract: Tuning the existing cathode surface to construct a hetero-interface configuration has been widely applied to improve its oxygen reduction reaction (ORR) activity. Here we report our findings on effective acceleration of the ORR kinetics of La2NiO4+δ (LNO) cathode by conformal Pr2NiO4+δ (PNO) modification. Meanwhile, the mechanism of the surface modification on ORR activity is revealed. Firstly, a highly active (110) plane for oxygen reduction emerges under LNO deposition. Secondly, the PNO modified layer with ~5 nm thick displays the smallest polarization resistance, which is 21 times less than that of LNO (~5 nm) referenced cathode. Meanwhile, PNO (~5 nm) heterojunction exhibits an alerted ORR kinetics because of different oxygen defect chemistries of the top layer, in which the porous LNO backbone provides a pathway to favorably transport both of oxygen ions and electrons, while the PNO decorating offers rich surface oxygen defects to further enhance the ORR activity.

Key words: solid oxide fuel cell, cathode film, surface modification, conformal heterojunction, oxygen reduction reaction activity