Single-Atom Zinc Sites with Synergetic Multiple Coordination Shells for Electrochemical H₂ O₂ Production.

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Single-atom catalysts (SACs) offer high efficiency but controlling their coordination environment is challenging.
• Simultaneous engineering of multiple coordination shells in SACs is crucial for optimizing catalytic performance.
• Developing advanced catalysts for selective oxygen reduction to hydrogen peroxide is vital.

Purpose of the Study:

• To develop a general two-step strategy for fabricating hollow carbon-based SACs with engineered multi-shell coordination.
• To investigate the synergistic effects of modulating the first and higher coordination shells of Zn-based SACs.
• To achieve highly selective electrochemical production of hydrogen peroxide.

Main Methods:

• Fabrication of hollow carbon-based single-atom catalysts (SACs) using a two-step strategy.
• Incorporation of sulfur atoms into higher coordination shells of Zn-N2O2 moieties (Zn-N2O2-S).
• Electrochemical characterization to evaluate oxygen reduction reaction (ORR) performance for hydrogen peroxide production.

Main Results:

• The Zn-N2O2-S SACs exhibit synergistic effects between the first (N2O2) and higher (S) coordination shells.
• Optimized electronic structure of Zn sites facilitates selective O2 reduction to H2O2.
• Achieved 96% selectivity for H2O2 production, a rate of 6.924 mol gcat-1 h-1 at 80 mA cm-2, and 93.1% Faradaic efficiency.
• Demonstrated excellent durability over 65 hours.

Conclusions:

• The engineered multi-shell coordination environment in Zn-N2O2-S SACs is key to high catalytic performance.
• This strategy provides a pathway for designing advanced SACs for selective electrochemical synthesis.
• The developed SACs show significant potential for efficient and sustainable hydrogen peroxide production.