Discovery of LaAlO<sub>3</sub> as an efficient catalyst for two-electron water electrolysis towards hydrogen peroxide.

Baek, Jihyun; Jin, Qiu; Johnson, Nathan Scott; Jiang, Yue; Ning, Rui; Mehta, Apurva; Siahrostami, Samira; Zheng, Xiaolin · Nat Commun · 2022

basic_science · Level V

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Abstract

Electrochemical two-electron water oxidation reaction (2e-WOR) has drawn significant attention as a promising process to achieve the continuous on-site production of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>). However, compared to the cathodic H<sub>2</sub>O<sub>2</sub> generation, the anodic 2e-WOR is more challenging to establish catalysts due to the severe oxidizing environment. In this study, we combine density functional theory (DFT) calculations with experiments to discover a stable and efficient perovskite catalyst for the anodic 2e-WOR. Our theoretical screening efforts identify LaAlO<sub>3</sub> perovskite as a stable, active, and selective candidate for catalyzing 2e-WOR. Our experimental results verify that LaAlO<sub>3</sub> achieves an overpotential of 510 mV at 10 mA cm<sup>-2</sup> in 4 M K<sub>2</sub>CO<sub>3</sub>/KHCO<sub>3</sub>, lower than those of many reported metal oxide catalysts. In addition, LaAlO<sub>3</sub> maintains a stable H<sub>2</sub>O<sub>2</sub> Faradaic efficiency with only a 3% decrease after 3 h at 2.7 V vs. RHE. This computation-experiment synergistic approach introduces another effective direction to discover promising catalysts for the harsh anodic 2e-WOR towards H<sub>2</sub>O<sub>2</sub>.