Ultrafine PtCo alloy by pyrolysis etching-confined pyrolysis for enhanced hydrogen evolution

Yi Zhang, Jianhong Lan, Yike Xu, Yuanyuan Yan, Weifeng Liu, Xuguang Liu, Shaonan Gu, Jiadong Zhou, Meiling Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

Zeolitic imidazolate framework-67 (ZIF-67) has been widely used as a precursor to developing efficient PtCo alloy catalysts for hydrogen evolution reaction (HER). However, traditional in-situ pyrolysis strategies involve complicated interface structure modulating processes between ZIF-67 and Pt precursors, challenging large-scale synthesis. Herein, a “pyrolysis etching-confined pyrolysis” approach is developed to design confined PtCo alloy in porous frameworks of onion carbon derived from ZIF-67. The confined PtCo alloy with Pt content of only 5.39 wt% exhibits a distinct HER activity in both acid (η10: 5 mV and Tafel: 9 mV dec−1) and basic (η10: 33 mV and Tafel: 51 mV dec−1) media and a drastic enhancement in stability. Density functional theory calculations reveal that the strong electronic interaction between Pt and Co allows favorable electron redistribution, which affords a favorable hydrogen spillover on PtCo alloy compared with that of pristine Pt(1 1 1). Operational electrochemical impedance spectroscopy demonstrates that the Faraday reaction process is facilitated under acidic conditions, while the transfer of intermediates through the electric double-layer region under alkaline conditions is accelerated. This work not only offers a universal route for high-performance Pt-based alloy catalysts with metal–organic framework (MOF) precursors but also provides experimental evidence for the role of the electric double layer in electrocatalysis reactions.

Original languageEnglish
Pages (from-to)997-1009
Number of pages13
JournalJournal of Colloid and Interface Science
Volume660
DOIs
Publication statusPublished - 15 Apr 2024

Keywords

  • Electric double layer
  • Faraday process
  • HER
  • PtCo alloy
  • Pyrolysis etching-confined pyrolysis

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