Electrochemical synthesis of hydrogen peroxide from oxygen
and water can be a cost-effective and energy-efficient alternative
to the traditional approach which requires high energy input and expensive
noble metal catalysts and has a large CO2 footprint. The
availability of selective electrocatalysts and performance validation
of a device represent current research needs toward this goal. Herein,
we report an efficient electrocatalytic system for hydrogen peroxide
production based on anthraquinone molecular catalysts which are tethered
onto carbon nitride (C3N4) conductive supports.
Anthraquinone enables highly selective synthesis of hydrogen peroxide
via two-electron oxygen reduction. The optimal electrolyte pH was
identified to both facilitate H2O2 electrochemical
synthesis and minimize H2O2 decomposition. The
anthraquinone-functionalized C3N4 supports were
then adapted into a gas diffusion cathode configuration to greatly
enhance the mass transport of oxygen reactants. The device fabricated
in this study achieved an optimal H2O2 production
rate of 60.1 mmol gcatalyst
–1 h–1 at a maximum Faradaic efficiency of 42.2%.