Efficient and durable electrochemical oxygen reduction to H2O2 in acidic media assisted through catalyst layer design

Electrochemical synthesis of hydrogen peroxide (H 2 O 2 ) through 2-electron oxygen reduction reaction (ORR) is a sustainable alternative to the industrialized anthraquinone oxidation process . Gas-diffusion electrode (GDE) is employed to overcome the mass transport limitation of O 2 to deliver high current density . However, long-term stability in practical electrolyzer with GDE is still challenging due to electrode flooding. Here, we propose a double catalyst layer (CL) strategy with gradient Nafion distribution to balance the mass transport of O 2 and H + and improve the flood-proof ability. Our design achieved H 2 O 2 production rate up to 2.16 mmol h −1 cm −2 with a selectivity of about 90% and enabled 48 h stable electrolysis at 100 mA cm −2 . Compared to the state-of-the-art H 2 O 2 electrosynthesis system in acidic media, the full-cell voltage improved significantly to 2.3 V at 100 mA cm −2 , indicating its potential for practical production and utilization.