Tailoring the d-band center of Ni on a dual-single-atom Ni–ZnNC catalyst for efficient H2O2 production

Abstract

Electrocatalytic oxygen reduction reaction (ORR) for H2O2 production presents an alternative approach suitable for on-site applications. Although atomically dispersed earth-abundant metal species anchored in a nitrogen-doped carbon framework (M–N–C) have demonstrated significant 2e− ORR activity, the Ni–N–C catalyst exhibits unfavorable catalytic activity. It is well-recognized that the d-band center of the metal can be tailored by introducing transition metals, thereby altering the adsorption free energy of the OOH∗ reactive species. Herein, we have designed a dual-single-atom configuration (Ni–ZnNC), where the Zn atom serves as a modulator to adjust the d-band electronic energy of the Ni center, ultimately optimizing the intermediate adsorption and resulting in high 2e− ORR performance. The Ni–ZnNC catalyst demonstrates an H2O2 production rate of 5.6 mol/g/h at 0.0 VRHE with a notable H2O2 selectivity of approximately 60% in an acid electrolyte. Density-functional theory calculations reveal that the Zn atom effectively alters the d-band electronic energy of the Ni center, strengthening the Ni–OOH∗ binding affinity and thereby enhancing the adsorption process. This work provides valuable insights into the design of earth-abundant metal Ni-based electrocatalysts for H2O2 generation.