Electrochemical synthesis of hydrogen peroxide (H2O2) via two-electron water oxidation reaction (2e-WOR) is an ideal process for delocalized production for water cleaning and other applications. Previously reported water oxidation catalysts have limited activity and selectivity, imposing a bottleneck for broad adaption of this technology. We identify ZnO as a new stable, non-toxic, active and selective catalyst for 2e-WOR to generate H2O2. Using density functional theory calculations, we propose that the (101 ̅0) facet of ZnO is an exceptional catalyst for 2e-WOR and confirm the prediction experimentally. We synthesize ZnO nanoparticles with a high fraction of (101 ̅0) facets and find that this catalyst gives an overpotential of 40 mV at 0.1 mA/cm2, and peak Faradaic efficiency of 81 % towards H2O2 evolution.
- Water oxidation catalysis
- Hydrogen peroxide synthesis
- Zinc oxide
- Density functional theory
Kelly, S., Shi, X., Back, S., Vallez, L., Park, S. Y., Siahrostami, S., Zheng, X., & Nørskov, J. K. (2019). ZnO as an Active and Selective Catalyst for Electrochemical Water Oxidation to Hydrogen Peroxide. ACS Catalysis, 9(5), 4593-4599. https://doi.org/10.1021/acscatal.8b04873