Approaching a high-rate and sustainable production of hydrogen peroxide: oxygen reduction on Co-N-C single-atom electrocatalysts in simulated seawater

• Published in: Energy & environmental science 2021-10, Vol.14 (1), p.5444-5456
• Main Authors: Zhao, Qinglan, Wang, Yian, Lai, Wei-Hong, Xiao, Fei, Lyu, Yuxiang, Liao, Caizhi, Shao, Minhua
• Format: Article
• Language: English
• Subjects: Air flow; Alternative energy sources; Anthraquinone; Anthraquinones; Catalysts; Chemical reduction; Cobalt; Electrocatalysts; Electrochemistry; Hydrogen peroxide; Hydrogen production; Oxygen; Oxygen reduction reactions; Seawater; Simulation; Sodium chloride; Sustainability; Sustainable production
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d1ee00878a

Electrochemical production of H 2 O 2 from O 2 using simulated seawater provides a promising alternative to the energy-intensive industrial anthraquinone process. In this study, a flow cell system is built for electrocatalytic production of H 2 O 2 under an air atmosphere in simulated seawater using cobalt single-atom catalysts (Co SACs). The Co SACs can achieve a high H 2 O 2 production rate of 3.4 mol g catalyst −1 h −1 under an air flow at a current density of 50 mA cm geo −2 and long-term stability over 24 h in 0.5 M NaCl. It is found that Co-N 5 rather than the Co-N 4 structure in Co SACs is the main active site for H 2 O 2 formation in the two-electron oxygen reduction reaction (ORR) pathway. It also shows high chloride-endurability without inhibition of the ORR process in simulated seawater. The fast production of H 2 O 2 on Co-N 5 sites in a flow cell provides a promising path of electrocatalytic oxygen reduction in simulated seawater, eventually converting ubiquitous air and seawater towards energy sustainability. Sustainable production of H 2 O 2 is boosted by oxygen reduction reaction on Co-N 5 sites in a flow cell in simulated seawater.