Structure-adaptive single-atom nickel catalysts for pure hydrogen peroxide electrosynthesis at industrial current density

The generation of pure hydrogen peroxide (H2O2) through two-electron oxygen reduction reaction represents a promising avenue for sustainable chemical production. However, a fundamental understanding of inevitable reconstruction of active sites during electrolysis remains elusive, hindering the development of dualable electrocatalysts. Herein, we report a structure-adaptive electrocatalyst featuring self-regulating capabilities under reaction. A series of single-atom Ni catalysts with B/N coordination (NiBxNy) serves as a model system to explore structure flexibility. Under the applied potential, the structural evolution of Ni+0.98-B2N2 into Ni+0.98-B1N2 occurs at initial stage. The Ni-B and Ni-N bond length in Ni+0.98-B1N2, as the genuine active site, are self-regulated to redistribute interfacial electrons by B/N coordination and then boost both intrinsic activity and stability of Ni site. When the potential is removed, the catalyst returns to its initial Ni-B2N2 configuration. The H2O2 productivity is up to 9320 mmol g catalyst-1 h-1 with a continuous output of ~5 wt% H2O2 solution under industrial current density for over 300 h. This work elucidates the dynamic reconstruction-activity enhancement for H2O2 electrosynthesis. The hydrogen peroxide generation represents a promising avenue for sustainable chemical production. Here, the authors report a structure-adaptive electrocatalyst that stabilizes the valence state of single-atom Ni sites during the reaction, enabling the continuous output of hydrogen peroxide at 300 mA cm−2.