Precise construction of RuPt dual single-atomic sites to optimize oxygen electrocatalytic behaviors for high-performance Zn-air batteries

Abstract

The development of redox bifunctional electrocatalysts with high performance, low cost, and long lifetimes is essential for achieving clean energy goals. This study proposed an atom capture strategy for anchoring dual single atoms (DSAs) in a zinc–zeolitic imidazolate framework (Zn–ZIF), followed by calcination under an N2 atmosphere to synthesize ruthenium–platinum DSAs supported on a nitrogen-doped carbon substrate (RuPt DSAs-NC). Theoretical calculations showed that the degree of Ru 5dxz − *O 2px orbital hybridization was high when *O was adsorbed at the Ru site, indicating enhanced covalent hybridization of metal sites and oxygen ligands, which benefited the adsorption of intermediate species. The presence of the RuPtN6 active center optimized the absorption–desorption behavior of intermediates, improving the electrocatalytic performance of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). RuPt DSAs-NC exhibited a 0.87 V high half-wave potential and a 268 mV low overpotential at 10 mA cm−2 in an alkaline environment. Furthermore, rechargeable zinc–air batteries (ZABs) achieved a peak power density of 171 mW cm−2. The RuPt DSAs-NC demonstrated long-term cycling for up to 500 h with superior round-trip efficiency. This study provided an effective structural design strategy to construct DSAs active sites for enhanced electrocatalytic performance.