Electrochemical generation of hydrogen peroxide from a zinc gallium oxide anode with dual active sites

作者：Li, Lejing; Hu, Zhuofeng^*; Kang, Yongqiang; Cao, Shiyu; Xu, Liangpang; Yu, Luo; Zhang, Lizhi^*; Yu, Jimmy C.^*

来源：Nature Communications, 2023, 14(1): 1890.

DOI：10.1038/s41467-023-37007-9

• 2-ELECTRON WATER OXIDATION
• H2O2 PRODUCTION
• PHOTOCATALYTIC ACTIVITY
• OXYGEN
• ELECTROCATALYST
• MECHANISM
• REDUCTION
• ZNGA2O4
• PD
• DECOMPOSITION

Developing efficient anodes for H2O2 production via water oxidation remains challenging. Here, the authors report a ZnGa2O4 anode with dual active sites to improve the selectivity and to resist the decomposition of H2O2, and the peak faradaic efficiency reaches 82% at a low potential. @@@ Electrochemical water oxidation enables the conversion of H2O to H2O2. It holds distinct advantages to the O-2 reduction reaction, which is restricted by the inefficient mass transfer and limited solubility of O-2 in aqueous media. Nonetheless, most reported anodes suffer from high overpotentials (usually >1000 mV) and low selectivity. Electrolysis at high overpotentials often causes serious decomposition of peroxides and leads to declined selectivity. Herein, we report a ZnGa2O4 anode with dual active sites to improve the selectivity and resist the decomposition of peroxides. Its faradaic efficiency reaches 82% at 2.3 V versus RHE for H2O2 generation through both direct (via OH-) and indirect (via HCO3-) pathways. The percarbonate is the critical species generated through the conversion of bicarbonate at Ga-Ga dual sites. The peroxy bond is stable on the surface of the ZnGa2O4 anode, significantly improving faradaic efficiency.

• 单位
  清华大学; 中山大学