Efficient hydrogen peroxide electrosynthesis using anthraquinone covalently bonded CNT on superhydrophobic air breathing cathode

Electrochemical H 2 O 2 production through two-electron oxygen reduction (ORR) is an environmentally friendly process with high energy efficiency. The low catalysts’ activity, low oxygen transfer rate and less device demonstration restrict the ORR development. In this study, a superhydrophobic air breathing cathode (ABC) was constructed, which consisted of anthraquinone covalently linked CNT-NH 2 (NCNT-AQ) and PTFE modified carbon felt. This ABC could keep stable liquid-gas-solid three phase interfaces and efficiently utilize O 2 through natural air diffusion, and the H 2 O 2 generation rate could arrive at 2.09 M g catalyst −1 h −1 at current density of 50 mA cm −2 , which was 4.45 times higher than traditional electrode. A flow cell was designed with this ABC, the concentration of produced H 2 O 2 could reach 0.26 M (8.84 g L −1 ) within 7 h, while the energy consumption was only 44.88 kWh kg −1 and the cost was estimated as 4.20 $ kg −1 . The application of this device was demonstrated by the treatment of organic polluted water and soil. This work presents a highly selective, durable, and low-cost H 2 O 2 electrosynthesis cell, providing a promising approach for the in-situ production and utilization of H 2 O 2 . • Molecular anthraquinone catalyst were introduced onto heterogeneous surfaces of CNT through chemical bonding. • The electrochemical H 2 O 2 production was significantly improved by anchoring anthraquinone onto CNT. • The superhydrophobic air breathing cathode greatly improved the oxygen transfer ability without the need to pump oxygen. • Device-level demonstrations showed the superior performance and stability of this superhydrophobic air breathing cathode.