Energy Environ. Sci.: The operation active sites of O2 reduction to H2O2 over ZnO

Title：

The operation active sites of O₂ reduction to H₂O₂ over ZnO

Authors：

Yunjie Zhou¹, Liang Xu¹, Jie Wu¹, Wenxiang Zhu¹, Tiwei He¹, Hao Yang¹, Hui Huang¹, Tao Cheng¹*, Yang Liu¹* and Zhenhui Kang^1,2 *

Institutions：

¹Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, China

²Macao Institute of Materials Science and Engineering (MIMSE), MUST-SUDA Joint Research Center for Advanced Functional Materials, Macau University of Science and Technology, Taipa 999078, Macao, China

Abstract：

The two-electron oxygen reduction reaction (2e⁻ORR) in neutral media is a promising method to achieve hydrogen peroxide (H₂O₂) from oxygen (O₂) directly in a sustainable way. Here, we show an ideal ZnO@ZnO₂ electrocatalyst for efficient O₂ reduction to H₂O₂ in a neutral medium. The in situ growth of ZnO₂ on ZnO forms the operation active sites, namely the heterogeneous interface between tetrahedral ZnO and octahedral ZnO₂, weakening the binding energies of both OOH* and O*. In a 0.1 M K₂SO₄ electrolyte, ZnO@ZnO₂ shows a H₂O₂ selectivity of nearly 100.0% via the ORR, while it can convert O₂ to H₂O₂ with a production rate of 5.47 mol g_cat⁻¹ h⁻¹ at 0.1 V vs. RHE and a Faraday efficiency (FE) of ∼95.5%, tested using a gas diffusion electrode device. The pulse voltage-induced current (PVC) was utilized in conjunction with a number of in situ characterization techniques and electrochemical studies to disclose the transformation of the ZnO surface and the production process of operational catalytic active sites on ZnO.

IF：

39.714

Link：

https://doi.org/10.1039/d3ee01788e