Electrochemical Pilot H <sub>2</sub> O <sub>2</sub> Production by Solid‐State Electrolyte Reactor: Insights From a Hybrid Catalyst for 2‐Electron Oxygen Reduction Reaction
S. Lin, Jun Wang, Junxiang Chen, Lin Peng, Huibing Wang, Junheng Huang, Zhenhai Wen
Abstract
Abstract The electrochemical oxygen reduction reaction (ORR) offers an alluring and sustainable alternative to the traditional anthraquinone process for hydrogen peroxide (H₂O₂) synthesis. However, challenges remain in developing scalable electrocatalysts and cost‐effective reactors for high‐purity H₂O₂ production. This study introduces a simple yet effective mechanical mixing method to fabricate a hybrid electrocatalyst from oxidized carbon nanotubes and layered double hydroxides (LDHs). This easily accessible and low‐cost catalyst achieves near‐perfect Faradaic efficiency (∼100%) with low overpotentials of 73 mV at 10 mA cm⁻ 2 and 588 mV at 400 mA cm⁻ 2 in a solid electrolyte cell. Through theoretical calculations and in‐situ analyses, we uncover the pivotal role played by the LDH co‐catalyst in fine‐tuning the local pH at the catalyst/solid‐electrolyte interface that drives both the activity and selectivity. We also design a low‐cost solid‐state reactor using cation‐exchange resin (CER) as both a proton conductor and a microchannel for efficient mass transfer, achieving a production rate of 5.29 mmol cm⁻ 2 h⁻¹ and continuous output concentrations of 11.8 wt.% H₂O₂. Scaled to an industrial area of 2 × 100 cm 2 , the pilot reactor achieves an impressive H₂O₂ production rate of approximately 127.0 mmol h⁻¹ at 15 A, marking a significant advancement in sustainable H₂O₂ production.