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The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
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Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
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Engineering Twins within Lattice-Matched Co/CoO Heterostructure Enables Efficient Hydrogen Evolution Reactions.

Taili Yang1, Yaotian Yan1, Ruonan Liu1

  • 1State Key Laboratory of Precision Welding and Joining of Materials and Structure, Harbin Institute of Technology, Harbin 150001, China.

Nano Letters
|April 23, 2025
PubMed
Summary

Engineered cobalt/cobalt oxide heterostructures with twin boundaries enhance hydrogen evolution reaction (HER) performance. This novel strain engineering approach optimizes electrocatalyst electronic structure for efficient water splitting.

Keywords:
hydrogen evolution reactionlattice distortionslattice matchthermal shocktwins

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Area of Science:

  • Materials Science
  • Electrochemistry
  • Nanotechnology

Background:

  • Twinning is a strain engineering strategy with potential for transition metal electrocatalysts.
  • Controllable construction and structure-activity relationships of twins in electrocatalysts are challenging.

Purpose of the Study:

  • To engineer a lattice-matched Co/CoO heterostructure with enriched twin boundaries.
  • To investigate the structure-activity relationships of twinning in electrocatalysts.
  • To optimize the electronic structure for the hydrogen evolution reaction (HER).

Main Methods:

  • Engineered Co/CoO heterostructure using flash Joule heating.
  • Utilized X-ray absorption fine structure (XAFS) analysis to study coordination numbers and atomic displacement.
  • Investigated electronic structure modifications, including d-band center downshifting and band flattening.

Main Results:

  • Achieved a Co/CoO heterostructure with enriched twin boundaries via lattice matching.
  • XAFS revealed reduced Co coordination numbers and substantial atomic displacement.
  • Demonstrated an ultralow overpotential of 49 mV at 10 mA cm-2 for HER in alkaline media.
  • Achieved remarkable stability over 500 h and efficient water splitting at a cell voltage of 2.05 V at 1 A cm-2.

Conclusions:

  • Coherent twinning interfaces induce strain, optimizing the electronic structure for HER.
  • The engineered heterostructure shows exceptional performance and stability for electrocatalytic water splitting.
  • This work provides a new pathway for designing high-performance electrocatalysts through controlled twinning.