Enabling direct H₂O₂ production through rational electrocatalyst design.

Future generations require more efficient and localized processes for energy conversion and chemical synthesis. The continuous on-site production of hydrogen peroxide would provide an attractive alternative to the present state-of-the-art, which is based on the complex anthraquinone process. The electrochemical reduction of oxygen to hydrogen peroxide is a particularly promising means of achieving this aim. However, it would require active, selective and stable materials to catalyse the reaction. Although progress has been made in this respect, further improvements through the development of new electrocatalysts are needed. Using density functional theory calculations, we identify Pt-Hg as a promising candidate. Electrochemical measurements on Pt-Hg nanoparticles show more than an order of magnitude improvement in mass activity, that is, Ag-1 precious metal, for H2O2 production, over the best performing catalysts in the literature

Building and identifying highly active oxygenated groups in carbon materials for oxygen reduction to H2O2

The one-step electrochemical synthesis of H2O2 is an on-site method that reduces dependence on the energy-intensive anthraquinone process. Oxidized carbon materials have proven to be promising catalysts due to their low cost and facile synthetic procedures. However, the nature of the active sites is still controversial, and direct experimental evidence is presently lacking. Here, we activate a carbon material with dangling edge sites and then decorate them with targeted functional groups. We show that quinone-enriched samples exhibit high selectivity and activity with a H2O2 yield ratio of up to 97.8 % at 0.75V vs. RHE. Using density functional theory calculations, we identify the activity trends of different possible quinone functional groups in the edge and basal plane of the carbon nanostructure and determine the most active motif. Our findings provide guidelines for designing carbon-based catalysts, which have simultaneous high selectivity and activity for H2O2 synthesis. The identity of catalytic sites for H2O2 generation in carbon-based materials remains controversial with limited experimental evidence to date. Here, the authors decorate various target functional groups on carbon materials and quinone-enriched samples exhibit the highest activity and selectivity