Efficient Hydrogen Peroxide Production at High Current Density by Gas Diffusion Electrode Based on Pristine Carbon Black

Abstract

H 2 O 2 production through electrochemical 2-electron reduction of oxygen (O 2 ) is a promising route whereas the faradaic efficiency is generally limited under high current density. In this work, a gas diffusion electrode (GDE) is fabricated with carbon black (CB, black pearls 2000) and PTFE by rolling method. On account of the porous surface with dominant meso and micro pores, high hydrophobic and abundant surface oxygen groups, the GDE exhibits H 2 O 2 yield of 85.2 ± 0.5 mg cm -2 h -1 , and current efficiency (CE) of 90.6 ± 0.4% at 151 mA cm -2 during a 20-cycle operation. Further elevating the current density to 301 mA cm -2 results in H 2 O 2 yield of up to 119.4 mg cm -2 h -1 while CE dropped to 62.3%. In addition, efficient H 2 O 2 yields are achieved at wide pH range of 1‒13. The applicability and stability of the GDE indicate its great potential for electrosynthesis of H 2 O 2 and electrochemical advanced oxidation processes at practical scales.