Bimetallic Ni/Co Single-Atom Catalysts Guided by Energy Descriptor for Efficient CO2 Electroreduction to Syngas

Abstract

Electrochemical CO₂ reduction to syngas (CO + H₂) offers a promising way to produce valuable chemicals and fuels from renewable electricity and captured CO₂, but developing efficient, tunable catalysts to control the syngas ratio remains challenging. Herein, we demonstrated the rational design of bimetallic Ni/Co single-atom catalysts for efficient, tunable CO₂ electroreduction to syngas. Adsorption energy descriptor was introduced to identify optimal Metal-N4 sites for CO₂ electroreduction, highlighting Ni-N4 and Co-N4 as promising candidates. Isolated Ni and Co atoms were precisely an-chored into nitrogen-doped carbon supports, forming Ni/Co-N4 active sites. Mechanistic insights revealed that atomic Ni-N4 sites selectively adsorbed and activated CO₂ to form CO, while Co-N4 sites bound H₂O to facilitate hydrogen evolution. This synergy between Co/Ni single-atom sites enabled high Faradaic efficiency and a tunable CO/H₂ ratio from 1:2.3 to 2.8:1. This research offers strategies for designing single-atom catalysts to achieve precise product selectivity control over energy-related applications.