Hydroxylated Boron Crystal Domain-Modulated Heterostructure Carbon Catalysts for Efficient Hydrogen Peroxide...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Metal-free heterostructure carbon catalysts are explored for electrochemical hydrogen peroxide (H₂O₂) synthesis via the two-electron oxygen reduction reaction (2e^- ORR).
• A key challenge is achieving stability at industrial current densities for sustainable H₂O₂ production.

Purpose of the Study:

• To develop a stable and highly active metal-free electrocatalyst for H₂O₂ synthesis.
• To address the limitations of traditional carbon-based catalysts at high current densities.

Main Methods:

• Synthesis of nano boron crystal domains (B_n) integrated into a carbon matrix (B_n-C catalyst).
• Electrochemical characterization including mass activity measurements and long-term stability tests at high current densities (>300 mA cm^-2).
• Computational modeling (Density Functional Theory) and in situ Raman spectroscopy to elucidate the catalytic mechanism.

Main Results:

• The B_n-C catalyst demonstrated high mass activity (11.6/10.7 mol g_cat^-1 h^-1) in alkaline/neutral electrolytes.
• Negligible loss in activity and over 90% Faradaic efficiency were observed during 100 hours of continuous electrolysis at high current density.
• The nano B_n domains enhanced O₂ enrichment and mass transfer, while -OH groups modulated the binding strength of the *OOH intermediate.

Conclusions:

• Nano boron crystal domains (B_n) in B_n-C catalysts overcome stability limitations for sustainable H₂O₂ production.
• The B_n-C catalyst is a promising alternative to metal-based catalysts for industrial-scale H₂O₂ synthesis due to its high activity and durability.