Linear Conjugated Polymers for Solar-Driven Hydrogen Peroxide Production: The Importance of Catalyst Stability

Hydrogen peroxide (H2O2) is one of the most important industrial oxidants. In principle, photocatalytic H2O2 synthesis from oxygen and H2O using sunlight could provide a cleaner alternative route to the current anthraquinone process. Recently, conjugated organic materials have been studied as photocatalysts for solar fuels synthesis because they offer synthetic tunability over a large chemical space. Here, we used high-throughput experiments to discover a linear conjugated polymer, poly(3-4-ethynylphenyl)ethynyl)pyridine (DE7), which exhibits efficient photocatalytic H2O2 production from H2O and O-2 under visible light illumination for periods of up to 10 h or so. The apparent quantum yield was 8.7% at 420 nm. Mechanistic investigations showed that the H2O2 was produced via the photoinduced stepwise reduction of O-2. At longer photolysis times, however, this catalyst decomposed, suggesting a need to focus the photostability of organic photocatalysts, as well as the initial catalytic production rates.

Automated summary

Conjugated organic materials have been studied as photocatalysts for solar fuels synthesis, with DE7 polymer discovered as an efficient catalyst for H2O2 production. Focus is needed on improving the photostability and initial catalytic production rates of organic photocatalysts.