Electrochemical hydrogen peroxide (H2O2) synthesis from water and air via two-electron (2e-) water oxidation or oxygen reduction reactions could provide a sustainable route for on-site H2O2 production. Unfortunately, the electrochemical H2O-to-H2O2 process usually suffers from limited selectivity under high current density. Here, we present an atomic Ni-doped TiO2 electrocatalyst that enables H2O2 production through 2e- water oxidation with high Faradaic efficiency of 70 at -300 mA cm -2. Furthermore, when paired with the 2e- oxygen reduction reaction using the oxidized carbon nanotube cathode, as high as 146 Faradaic efficiency for H2O2 is achieved at 240 mA in a full flow cell device. Moreover, this device could be operated for modular H2O2 synthesis with a production rate of 109.12 mmol min -1 (i.e., 3.7 mg min -1). This work demonstrates the atomically controlled metal oxide electrocatalyst for harsh anodic H2O to H2O2 and the practical applicability for the on-site H2O2 production from earth-abundant resources.
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机译：通过双电子（2e-）水氧化或氧还原反应从水和空气中电化学合成过氧化氢（H2O2）可以为现场生产H2O2提供可持续的途径。不幸的是，电化学 H2O-to-H2O2 工艺在高电流密度下通常选择性有限。在这里，我们提出了一种原子掺杂的TiO2电催化剂，该催化剂通过2e-水氧化生产H2O2，在-300 mA cm -2下具有70%的高法拉第效率。此外，当与使用氧化碳纳米管阴极的2e-氧还原反应配合使用时，在全流通池装置中，在240 mA下可实现高达146%的H2O2法拉第效率。此外，该装置可用于模块化 H2O2 合成，生产速率为 109.12 mmol min -1（即 3.7 mg min -1）。本工作证明了原子控制金属氧化物电催化剂对苛刻阳极H2O制H2O2的实际应用，以及在地球资源丰富的现场生产H2O2的实际应用。
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