Discovery of LaAlO3 as an efficient catalyst for two-electron water electrolysis towards hydrogen peroxide.

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 (H2O2). However, compared to the cathodic H2O2 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 LaAlO3 perovskite as a stable, active, and selective candidate for catalyzing 2e-WOR. Our experimental results verify that LaAlO3 achieves an overpotential of 510 mV at 10 mA cm-2 in 4 M K2CO3/KHCO3, lower than those of many reported metal oxide catalysts. In addition, LaAlO3 maintains a stable H2O2 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 H2O2.