Super-Coordinated Nickel N4Ni1O2 Site Single-Atom Catalyst for Selective H2O2 Electrosynthesis at High Current Densities

Electrochemical production of hydrogen peroxide (H2O2) from O-2 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.