Manipulating oxygenate adsorption on N-doped carbon by coupling with CoSn alloy for bifunctional oxygen electrocatalyst

Highly active bifunctional oxygen electrocatalysts accelerate the development of high-performance Zn-air battery, but suffer from the mismatched activities of oxygen evolution reaction (OER) and oxygen reduced reaction (ORR). Herein, highly integrated bifunctional oxygen electrocatalysts, cobalt-tin alloys coated by nitrogen doped carbon (CoSn@NC) are prepared by MOFs-derived method. In this hybrid catalyst, the binary CoSn nanoalloys mainly contribute to highly active OER process while the Co (or Sn)-N-C serves as ORR active sites. Rational interaction between CoSn and NC donates more rapid reaction kinetics than Pt/C (ORR) and IrO2 (OER). Such CoSn@NC holds a promise as air-cathode electrocatalyst in Zn-air battery, superior to Pt/C + IrO2 catalyst. First-principles calculations predict that CoSn alloys can upgrade charge redistribution on NC and promote the transfer to reactants, thus optimizing the adsorption strength of oxygen-containing intermediates to boost the overall reactivity. The tuning of oxygenate adsorption by interactions between alloy and heteroatom-doped carbon can guide the design of bifunctional oxygen electrocatalysts. & COPY; 2022 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).