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<p>The long-standing challenges facing Pt-based alloy catalysts in oxygen reduction reactions (ORRs) are rapid oxidation and loss of transition metal/Pt in proton exchange membrane fuel cells (PEMFCs). In this work, we report a concept of “covalentization” in intermetallic L1<sub>0</sub>-PtMM’ (M = Fe, Co, Ni and M’ = one of the 4<sup>th</sup>-period elements (from Ti to Ge)) alloys to enhance their electrochemical stability. Specifically, the formation of a quasi-covalent bond network in L1<sub>0</sub>-PtMM’ due to the less occupied antibonding states induced by high <i>d</i>-band positions of M’ elements (e.g., Ti, V, Cr) enhances atomic bond order and strength, diminishing Co anodic dissolution via strengthened Pt/Co-M’ bonds and reducing Co cathodic corrosion by inhibiting Pt oxidation through an electron buffering effect. The developed L1<sub>0</sub>-PtCoCr/C catalysts show a high mass activity (MA = 1.27 A mg<sub>Pt</sub><sup>−1</sup>) and rated power (16.5 W mg<sub>Pt</sub><sup>−1</sup>) in PEMFCs at a low total Pt loading of 0.075 mg<sub>Pt</sub> cm<sup>−2</sup>. The catalysts also exhibit high electrochemical stability with ~3% and 5% loss of MA and rated power after 30,000 accelerated durability testing cycles and projects a lifetime of about 42,000 hours.</p>

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Regulating orbital interaction to construct quasi-covalent bond networks in Pt intermetallic alloys for high-performance fuel cells

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2025年5月27日

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  • Xuan Liu,
  • Yuhan Wang,
  • Hu He,
  • Zhonglong Zhao,
  • Xuan Luo,
  • Siyang Zhang,
  • Gang Lu,
  • Dong Su,
  • Yucheng Wang,
  • Yunhui Huang,
  • Qing Li

摘要

The long-standing challenges facing Pt-based alloy catalysts in oxygen reduction reactions (ORRs) are rapid oxidation and loss of transition metal/Pt in proton exchange membrane fuel cells (PEMFCs). In this work, we report a concept of “covalentization” in intermetallic L10-PtMM’ (M = Fe, Co, Ni and M’ = one of the 4th-period elements (from Ti to Ge)) alloys to enhance their electrochemical stability. Specifically, the formation of a quasi-covalent bond network in L10-PtMM’ due to the less occupied antibonding states induced by high d-band positions of M’ elements (e.g., Ti, V, Cr) enhances atomic bond order and strength, diminishing Co anodic dissolution via strengthened Pt/Co-M’ bonds and reducing Co cathodic corrosion by inhibiting Pt oxidation through an electron buffering effect. The developed L10-PtCoCr/C catalysts show a high mass activity (MA = 1.27 A mgPt−1) and rated power (16.5 W mgPt−1) in PEMFCs at a low total Pt loading of 0.075 mgPt cm−2. The catalysts also exhibit high electrochemical stability with ~3% and 5% loss of MA and rated power after 30,000 accelerated durability testing cycles and projects a lifetime of about 42,000 hours.