Controllable synthesis of CoN3 catalysts derived from Co/Zn-ZIF-67 for electrocatalytic oxygen reduction in acidic electrolytes

Research output: Contribution to journalArticlepeer-review

Authors

  • Shoujuan Lai
  • Li Xu
  • Hongli Liu
  • Shuai Chen
  • Lijie Zhang
  • Jin Sun
  • Dongjiang Yang
  • Xiaoliang Zhao

Colleges, School and Institutes

External organisations

  • Qingdao University
  • Jiangsu University
  • Institute of Coal Chemistry Chinese Academy of Sciences
  • Griffith University

Abstract

Metal nitrides have attracted significant attention due to their noble metal-like electron features; however, their applications are still limited by numerous predicaments in their synthesis owing to their large bond enthalpy and high ionization potential, which is generally implemented under extra-high pressure and temperature. Herein, the controllable synthesis of CoN3 nanoparticles embedded in graphite carbon was successfully achieved through the in situ pyrolysis of a Co/Zn-ZIF-67 (ZIF, zeolitic imidazolate framework) precursor (Co/Zn molar ratio ranging from 5/95 to 9/91 in Zn-ZIF-67 crystals). During the pyrolysis, the Co/Zn-ZIF-67 precursor was first converted into Co nanoparticles (NPs) embedded in N-doped porous carbon (Co@NC), accompanied by the release of NH3 from the decomposition of the ZIF structure. The abundant micropores formed by the evaporation of Zn and large surface area of Co@NC facilitate the contact between NH3 molecules and Co, generating CoN3 species. Importantly, when the CoN3@NC-7-1000 sample was evaluated as an electrocatalyst for the oxygen reduction reaction (ORR), it exhibited high performance with a positive half-wave potential (0.72 V vs. RHE) and a high current density (5.40 mA cm-2) in the 0.5 M H2SO4 electrolyte. According to the density functional theory (DFT) calculation, the exposed (220) facet of CoN3 with a low energy barrier can benefit the adsorption of O2 molecules.

Bibliographic note

Funding Information: We are grateful for the nancial support by the National Natural Science Foundation of China (grant no. 21501105, 51808303 and 51672143), Taishan Scholars Program, Taishan Scholar Foundation (ts201511019), the Applied Basic Research of Qingdao City (Special Youth Project) (no. 19-6-2-74-cg) and Outstanding Youth of Natural Science in Shandong Province (JQ201713). Publisher Copyright: © 2019 The Royal Society of Chemistry. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.

Details

Original languageEnglish
Pages (from-to)21884-21891
Number of pages8
JournalJournal of Materials Chemistry A
Volume7
Issue number38
Publication statusPublished - 2019