Breaking the Activity-Stability Trade-Off in Oxygen Evolution Catalysis via Self-Limiting Atomic-Spacing Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical water splitting requires efficient catalysts for oxygen evolution reaction (OER).
• Conventional OER pathways face activity-stability trade-offs.
• Oxygen pathway mechanism (OPM) offers an alternative but needs precise atomic control.

Purpose of the Study:

• To develop a catalyst with atomic-level control over intermetallic distances for OER.
• To enable the oxygen pathway mechanism (OPM) by engineering atomic spacing.
• To break the activity-stability compromise in non-precious OER catalysts.

Main Methods:

• Self-limiting atomic-spacing engineering by grafting an 'active skin' onto CoMoO4 (AS@CMO).
• Utilizing intrinsic metal leaching for precision regulation of Co-Co distance.
• In situ formation of a metal-coordination polymer layer to suppress metal dissolution and optimize spacing.

Main Results:

• Atomic spacing control switched OER pathways: pristine CMO (3.34 Å) followed adsorbate evolution mechanism (AEM), defect-overloaded systems (2.59 Å) followed lattice oxygen mechanism (LOM), and AS@CMO (2.83 Å) achieved OPM.
• AS@CMO catalyst showed low OER overpotential (η10 = 1.48 V) and 400-h stability.
• AS@CMO demonstrated enhanced hydrogen evolution activity (η10 = 78 mV) and outperformed noble-metal benchmarks in overall water splitting.

Conclusions:

• Self-limiting atomic-spacing engineering provides a paradigm for OER pathway control.
• This method successfully breaks the activity-stability trade-off in non-precious catalysts.
• The AS@CMO catalyst offers a highly efficient and stable solution for electrochemical water splitting.