Unlocking Stable H2O2 Electrosynthesis by Passivating Defects in Reduced Graphene Oxide

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical synthesis of hydrogen peroxide (H2O2) is limited by catalyst activity-stability trade-offs.
• Catalyst defects enhance activity but cause overstabilization of intermediates, leading to degradation.

Purpose of the Study:

• To engineer a durable catalyst for efficient electrochemical H2O2 synthesis.
• To address the overstabilization of the *OOH intermediate and catalyst degradation.

Main Methods:

• Engineered an asymmetric O-Si-N-C structure at the SiOx/Si-N-rGO interface.
• Utilized experimental studies and microkinetic modeling.
• Investigated electronic regulation via nitrogen's electron-buffering capacity.

Main Results:

• The O-Si-N-C interface electronically regulated carbon sites, weakening *OOH adsorption.
• Nitrogen facilitated spatial charge transfer, optimizing *OOH binding within the Sabatier region.
• The Si-N-rGO catalyst demonstrated stable operation (>160 h) at 300 mA cm-2, producing 5.0 wt% H2O2 with 80% Faradaic efficiency.

Conclusions:

• The engineered interface suppresses radical-mediated degradation by optimizing intermediate adsorption.
• This work provides a design strategy for durable catalysts for industrial-scale H2O2 electrosynthesis.