A H2O2 electrosynthesis catalyst containing super-coordinated single nickel sites, that is, ones coordinated by four nitrogen and two O atoms (i.e., N4Ni1O2) on carboxyl functionalized multiwall carbon nanotubes is developed. It gives a 2 e− oxygen reduction reaction (ORR) with a cathodic energy efficiency of approximately 82 % and a H2O2 Faradaic efficiency (FE) of around 96 % at a current density of 200 mA cm−2.
Electrochemical production of hydrogen peroxide (H2O2) from O2 on single-atom catalysts has attracted great attention, yet the quest for robust catalysts is driven by achieving >90 % Faradaic efficiency (FE) under industrial-relevant current densities (>100 mA cm−2). Herein we synthesize a catalyst that contains single nickel site coordinated by four nitrogen and two oxygen atoms (i.e., N4Ni1O2) via involving carboxyl functionalized multiwall carbon nanotubes as a substrate to provide extra O coordination to the regular NiN4 site. It has a cathodic energy efficiency of approximately 82 % and a H2O2 FE of around 96 % at 200 mA cm−2 current density, outperforming the reported single-atom catalysts for H2O2 electrosynthesis.Zum Volltext