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

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 (similar to 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.

Automated summary

This study demonstrates a low-cost activated coke electrocatalyst with size-tailored amorphous carbon clusters doped by oxygen groups, showing high performance in alkaline systems for the electrochemical oxygen reduction reaction to generate H2O2. The results reveal the crucial role of carbon cluster size and oxygen doping in the H2O2 electrochemical production process.