Indirect H2O2 synthesis without H2

Abstract Industrial hydrogen peroxide (H 2 O 2 ) is synthesized using carbon-intensive H 2 gas production and purification, anthraquinone hydrogenation, and anthrahydroquinone oxidation. Electrochemical hydrogenation (ECH) of anthraquinones offers a carbon-neutral alternative for generating H 2 O 2 using renewable electricity and water instead of H 2 gas. However, ECH has not yet had an impact on the industry because H 2 O 2 formation rates are too low for commercialization. We report here that a membrane reactor enabled us to hydrogenate anthraquinone (0.25 molar) with a current efficiency of > 80% at current densities of 75 milliamperes per square centimeter. We also demonstrate continuous H 2 O 2 synthesis from the hydrogenated anthraquinones over the course of 48 hours. This study represents the fastest rates of electrochemical anthraquinone hydrogenation ever reported (1.32 ± 0.14 millimoles per hour normalized per centimeter squared of geometric surface of electrode), and provides a pathway toward carbon-neutral H 2 O 2 synthesis.