High surface area N/O co-doped carbon materials: Selective electrocatalysts for O-2 reduction to H2O2

摘要

The search for a sustainable process for production of hydrogen peroxide (H2O2) is receiving a great attention in the last years in view of its possible use as a clean oxidant in the chemical industry or for decontamination of water streams. In this context, the electrochemical approach is particularly interesting, since it can use electricity produced from solar light through photovoltaic panels. H2O2 can be produced by selective 2-electron reduction of O-2 from air, but the efficiency of this process is strongly limited by possible concomitant 4-electron reduction to H2O. Graphitic carbon materials have been reported as selective electrocatalysts in 2-electron O-2 reduction, with recognized as active sites for the process. In this work, we present the preparation of high surface area graphitic carbons containing O and N as dopants, with optimal porosity and tunable composition depending on the molar ratio of the molecular precursors employed in the preparation. We observed that a tiny amount of N within the material can improve the selectivity to H2O2, without significant loss of performances. The addition of Cu nanoparticles deeply changes the selectivity of the systems, favoring the O-2 reduction to H2O with a very low selectivity to H2O2.