Atomically\nDispersed Nickel Coordinated with Nitrogen\non Carbon Nanotubes to Boost Electrochemical CO₂ Reduction

Abstract

Single-atom catalysts (SACs) are being widely developed\nfor the\nCO₂ reduction reaction (CO₂RR) because of their\nremarkable activity and selectivity. However, insufficient CO₂RR performance and the poor long-term stability of the SACs\nremain obstacles to process scale-up. Herein, we explore Ni SACs (Ni-N/NCNT)\nunder practical conditions using a zero-gap CO₂ electrolyzer\nfor CO production. We demonstrate that the CO₂RR performance\nof the Ni-N/NCNT results from the suitable Ni–N–C, which\nenhanced electron transfer and increased CO₂ adsorption.\nFurthermore, we propose a strategy for improving the CO₂RR performance and long-term stability by focusing on the membrane\nelectrode assembly (MEA) structure. A maximum Faradaic efficiency\nof 96.73% (at 2.1 V) and partial current density of 219.49 mA cm^–2 (at 2.4 V) for CO production were obtained on the\nMEA with the Ni-N/NCNT catalyst and the Sustainion (Sust.) membrane.\nIn addition, MEA with Sust. exhibited long-term stability at −100\nmA cm^–2 for over 60 h.