Direct Hydrogen Peroxide Synthesis on a Sn-doped CuWO<sub>4</sub>/Sn Anode and an Air-Breathing Cathode
Lejing Li, Liangpang Xu, Alice W. M. Chan, Zhuofeng Hu, Ying Wang, Jimmy C. Yu
Abstract
Electrosynthesis of H2O2 from simultaneous water oxidation reaction (WOR) and oxygen reduction reaction (ORR) is a promising alternative to the traditional anthraquinone oxidation process. However, this approach suffers from sluggish kinetics and poor selectivity of the two-electron transfer WOR to H2O2. Most of the current reported metal oxide materials require a large overpotential (more than 1 V), and the H2O2 production rate is quite low (usually lower than ∼5 μmol min–1 cm–2). In this work, a new anode material, CuWO4/Sn, has been developed to overcome these limitations. At an overpotential of only 0.74 V, a H2O2 Faradaic efficiency (FE) as high as 72% can be achieved for the 2e-WOR. By integrating this anode with the ORR at an air-breathing cathode, an overall FEcell of 161% is obtained here, with a theoretical FE as high as 200%. The integrated cell achieves a maximum H2O2 yield of 66 μmol min–1 at 140 mA. This design is of guiding significance for future efforts to obtain high value-added chemicals from two electrodes simultaneously.