Geometric structures, electronic characteristics, stabilities, catalytic activities, and descriptors of graphene-based single-atom catalysts

Abstract

Single-atom catalysts (SACs) have been a research hotspot due to their high catalytic activity, selectivity, and atomic utilization rates. However, the theoretical research of SACs is relatively fragmented, which restricts further understanding of SAC stability and activity. To address this issue, we report our analysis of the geometric structures, electronic characteristics, stabilities, catalytic activities, and descriptors of 132 graphene-based single-atom catalysts (M/GS) obtained from density functional theory calculations. Based on the calculated formation and binding energies, a stability map of M/GS was established to guide catalyst synthesis. The effects of metal atoms and support on the charge of metal atoms are discussed. The catalytic activities of M/GS in both nitrogen and oxygen reduction reactions are predicted based on the calculated magnetic moment and the adsorption energy. Combined with the electronegativity and d-band center, a two-dimensional descriptor is proposed to predict the O adsorption energy on M/GS. More importantly, this theoretical study provides predictive guidance for the preparation and rational design of highly stable and active single-atom catalysts using nitrogen doping on graphene.

Keywords

• Single-atom catalyst
• Graphene
• Stability
• Activity
• Density functional theory
• Reaction descriptor