ZnO As an Active and Selective Catalyst for Electrochemical Water Oxidation to Hydrogen Peroxide

Sara R. Kelly, Xinjian Shi, Seoin Back, Lauren Vallez, So Yeon Park, Samira Siahrostami, Xiaolin Zheng, Jens K. Nørskov
Year of publication: 
ACS Catalysis

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 adoption of this technology. We identify ZnO as a new stable, nontoxic, active, and selective catalyst for 2e-WOR to generate H2O2. Using density functional theory calculations, we propose that the (1010) facet of ZnO is an effective catalyst for 2e-WOR and confirm the prediction experimentally. We synthesize ZnO nanoparticles with a high fraction of (1010) facets and find that this catalyst gives an overpotential of 40 mV at 0.1 mA/cm2 and peak Faradaic efficiency of 81% toward H2O2 evolution.

Acknowlegment: This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science, via Grant DE-SC0008685 to the SUNCAT Center of Interface Science and Catalysis. X.Z. thanks the generous support of the Stanford Woods Institute for the Environment and the Stanford Natural Gas Initiative.

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