Direct HO Synthesis, without H Gas.

We report here the direct hydrogenation of O gas to form hydrogen peroxide (HO) using a membrane reactor without H gas. Hydrogen is sourced from water, and the reactor is driven by electricity. Hydrogenation chemistry is achieved using a hydrogen-permeable Pd foil that separates an electrolysis chamber that generates reactive H atoms, from a hydrogenation chamber where H atoms react with O to form HO. Our results show that the concentration of HO can be increased ∼8 times (from 56.5 to 443 mg/L) by optimizing the ratio of methanol-to-water in the chemical chamber, and through catalyst design. We demonstrate that the concentration of HO is acutely sensitive to the HO decomposition rate. This decomposition rate can be minimized by using AuPd alloy catalysts instead of pure Pd. This study presents a new pathway to directly synthesize HO using water electrolysis without ever using H gas.