Simulation-guided atomic Ni catalyst with oxygen-enriched coordination environment for H2O2 electrosynthesis coupled with 5-HMF oxidation

Abstract

The electrosynthesis of H₂O₂ production via the two-electron oxygen reduction reaction (2e-ORR) has attracted increasing attention. In this work, a novel Ni-N-C single-atom catalyst (SAC) with Ni-N₄O₁ coordination and a C-O-C synergistic structure is screened out. The corresponding SAC is then synthesized via chelation annealing. During the 2e-ORR test, the Ni-NOC exhibits an H₂O₂ selectivity of 92.7% at 0.5 V vs. reversible hydrogen electrode (RHE), and the H₂O₂ production rate can reach 252.91 mmol h⁻¹ g⁻¹ with a TOF of 0.187 s⁻¹, which is among the best Ni-N-C catalysts. In addition, the cathodic 2e-ORR on this SAC is successfully coupled with the anodic oxidation of 5-HMF, and an overpotential of 0.32 V is achieved for 5-HMF oxidation at 50 mA, much smaller than the traditional oxygen evolution reaction (OER) process. Hence, this work provides a promising strategy for designing highly active 2e–ORR SACs as well as a novel coupling system of H₂O₂ production and 5-HMF electrooxidation.