Acta Phys. -Chim. Sin. ›› 2024, Vol. 40 ›› Issue (6): 2306013.doi: 10.3866/PKU.WHXB202306013

Special Issue: Frontiers in Electrochemistry

• ARTICLE • Previous Articles     Next Articles

Regulating the High Entropy Component of Double Perovskite for High-Temperature Oxygen Evolution Reaction

Weicheng Feng1,2, Jingcheng Yu1,2, Yilan Yang3, Yige Guo1,2, Geng Zou1,2, Xiaoju Liu4, Zhou Chen5, Kun Dong6, Yuefeng Song1,*, Guoxiong Wang1,*, Xinhe Bao1   

  1. 1 State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning Province, China
    2 College of Energy, University of Chinese Academy of Sciences, Beijing 100049, China
    3 School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, Liaoning Province, China
    4 School of Chemistry and Chemical Engineering, Yulin University, Yulin 719100, Shannxi Province, China
    5 College of Materials, Xiamen University, Xiamen 361005, Fujian Province, China
    6 Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2023-06-05 Revised:2023-07-31 Accepted:2023-07-31 Published:2023-11-29
  • Contact: Email: songyf2014@dicp.ac.cn (Yuefeng Song)wanggx@dicp.ac.cn; Tel.: +86-411-84379976 (Guoxiong Wang)
  • Supported by:
    the National Key R & D Program of China(2021YFA1502400); the National Natural Science Foundation of China(22272176); the National Natural Science Foundation of China(22002166); the National Natural Science Foundation of China(22125205); the National Natural Science Foundation of China(22072146); the National Natural Science Foundation of China(22002158); the DNL Cooperation Fund, CAS(DNL202007); the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2022008); the CAS Youth Innovation Promotion(Y201938)

RichHTML

8

Full text @ ScienceDirect

Like

Supplement

1

Abstract:

Solid oxide electrolysis cells (SOECs) could convert CO2 to CO powered by clean electricity with low overpotential, high Faradaic efficiency, and high current density. Since the performance of SOEC is affected by sluggish oxygen evolution reaction (OER) kinetics at the anodes, the modification of anode materials is crucial for the further application of SOEC. Perovskites with high configurational entropy exhibit high catalytic activity in many reactions, but are rarely reported in SOECs. Herein, two kinds of high entropy perovskites (HEPs), with formulas of (Pr0.2La0.2Sm0.2Nd0.2Gd0.2)BaCo2O6−δ (A-HEP) and Pr(Ba0.2Sr0.2Ca0.2Na0.2K0.2) Co2O6−δ (A′-HEP), are synthesized by doping different rare earth metal, and alkaline metal or alkaline earth metal ions into A-site and A′-site of the double perovskites. Rietveld refinement of X-ray diffraction patterns and elemental maps of scanning electron microscope images confirm the successful synthesis of the two samples. The tetragonal double perovskite structure of A-HEP and the transformation to orthorhombic structure of A′-HEP due to the difference in average atomic radii and oxidation states of the doped ions are also detected. Co 2p X-ray photoelectron spectroscopy (XPS) and O K-edge X-ray absorption spectroscopy reveal that the average oxidation state of Co is lifted from +3.23 in Aʹ-HEP to +3.39 in A-HEP, and the hybridization of Co 2p and O 1s orbitals is also enhanced in A-HEP, which increase the electron transfer pathway and reduce the transfer barrier. Therefore, the electrical conductivity of A-HEP at 800 ℃ is higher than that of Aʹ-HEP. Moreover, the increased absorption oxygen species concentration of A-HEP in O 1s XPS and O2-temperature programmed desorption results indicates more surface oxygen vacancies, thus increasing active sites for the anodic OER. Consequently, the anodic polarization resistances related to oxygen transportation, electron transfer and surface reaction processes are decreased remarkably in A-HEP, resulting in a high current density of 1.76 A∙cm−2 at 800 ℃ and a stability of 200 h. This work presents a new method for designing high-performance HEPs as SOEC anode materials.

Key words: Solid oxide electrolysis cell, High entropy perovskite, Oxygen evolution reaction, Oxygen vacancy, Electron transfer