Graphdiyne-Supported Single-Atom-Sized Fe Catalysts for the Oxygen Reduction Reaction: DFT Predictions and Experimental Validations

Abstract

Single-atom-sized catalysts (often called single atom catalysts) are highly desired for maximizing the efficiency of metal atom use. However, their synthesis is a major challenge that largely depends on finding an appropriate supporting substrate to achieve a well-defined and highly dispersed single atom. This work demonstrates, based on density functional theory (DFT) predictions and experimental validations, that graphdiyne is a good substrate for anchoring Fe atoms through the formation of covalent Fe–C bonds to produce graphdiyne-supported single-atom-sized Fe catalysts (Fe–graphdiyne catalysts); moreover, this catalyst shows high catalytic activity to oxygen reduction reactions (ORRs) similar to or even slightly better than the precious metal benchmark (commercial 20 wt % Pt/C catalyst). DFT predicts that the O2 molecule can bind with an Fe atom, and the electron transformation process of ORRs occurs through a 4e– pathway. To validate the theoretical predictions, the Fe–graphdiyne catalyst was then s...