Inexpensive activated coke electrocatalyst for high-efficiency hydrogen peroxide production: Coupling effects of amorphous carbon cluster and oxygen dopant

Abstract Electrochemical oxygen reduction has been regarded as a promising choice to enable H2O2 on-site production and utilization wherein the exploration of high-efficiency yet cost-effective catalysts is the key. Here, we demonstrate a low-cost activated coke (AC) electrocatalyst with size-tailored amorphous carbon clusters doped by oxygen groups, prepared through a facile CO2 assisted mechanochemistry approach, to deliver among the highest performances reported in a typical alkaline system, including high activity (onset potential of 0.83 V), high H2O2 selectivity (∼90 %) and long-term stability. A series of control experiments, structural characterizations before and after electrochemical tests and density functional theory calculations provide a new insight into the coupling role of carbon cluster size and oxygen doping in H2O2 electrochemical production process, that is, size-reduced amorphous carbon lattices with abundant edges contribute to the high activity, while the basal carbon atoms in ether-doped small-size carbon plane are the most active sites towards H2O2 selectivity.