Efficient Electrochemical Oxygen Reduction to Hydrogen Peroxide Production from Nickel-Nitrogen-Doped Mesoporous Graphene Catalyst

Hydrogen peroxide(H 2 O 2 ) is an excellent oxidizing agent with various uses in industrial bleaching, chemical synthesis, and wastewater treatment. Because of its wide range of applications, the global market demand is rapidly increasing. At present, over 95 % of H 2 O 2 is produced through the anthraquinone process which is an environmentally unfriendly process. Therefore, numerous studies have focused on replacing this process for H 2 O 2 with more eco-friendly processes. One of the alternative methods is the electrochemical production of H 2 O 2 through oxygen reduction reaction(ORR), which offers an economical and environmentally friendly route to H 2 O 2 . The oxygen reduction reaction involves a multielectron transfer process in which O 2 can be reduced to produce H 2 O in a four-electron process or undergo a two-electron pathway to form H 2 O 2 . However, the design of selective and active electrocatalysts remains a challenge due to competitive reaction pathways between two-electron and four-electron reduction. We develop 3D mesoporous graphene with high H 2 O 2 production in neutral electrolytes by adjusting the pore size and regulating the atmosphere of Nickel single atom. This catalyst has 3D interconnected hollow N-doped graphene shells and Nickel single atoms will be atomically dispersed on N-doped graphene shells. The mesoporous structure with a large surface area accelerates mass transport. Moreover, electron-poor Nickel atoms yield high selectivity above 90 % and high activity for electrochemical oxygen reduction to produce H 2 O 2 in neutral conditions. This result represents a benchmark for the two-electron ORR electrocatalyst in the neutral conditions.