Catalytic activity of OH functionalized N-doped graphene in oxygen reduction reaction for fuel cell applications: a DFT study

Catalytic behavior of metal-free hydroxyl group (OH) functionalized single nitrogen (N-Gra(OH)(16)) and triple nitrogen (N-3-Gra(OH)(16)) doped graphene surface are investigated in the 4e(-) reduction pathway under oxygen reduction reaction (ORR) process. The thermodynamical parameters indicate that the reaction is highly exothermic and feasible with the N-Gra(OH)(16) and N-3-Gra(OH)(16) as catalysts. However, N-3-Gra(OH)(16) exhibits better catalytic properties than N-Gra(OH)(16.) The chemisorption of all reactive species (*O-2, *OOH, *O and *OH) via a covalent bond on the N-3-Gra(OH)(16) and the physisorption of the product H2O on the N-3-Gra(OH)(16) are essential for efficient reaction kinetics and the uninterrupted reaction cycle, respectively. Categorically, due to the presence of a large number of nitrogen atoms, the N-3-Gra(OH)(16) exhibits excellent catalytic activity which has resulted in lowered EHOMO-LUMO gap, concomitantly increasing the surface's reactivity. Besides the above, the barrier energies are comparable with platinum (Pt) catalysts. Our results show that the N-3-Gra(OH)(16) surface is the most suitable catalyst for ORR activity.

Automated summary

The catalytic behavior of metal-free hydroxyl group (OH) functionalized single nitrogen (N-Gra(OH)(16)) and triple nitrogen (N-3-Gra(OH)(16)) doped graphene surface in the 4e(-) reduction pathway under oxygen reduction reaction (ORR) process has been studied. The thermodynamic parameters indicate that the reaction is highly exothermic and feasible with N-Gra(OH)(16) and N-3-Gra(OH)(16) as catalysts. N-3-Gra(OH)(16) exhibits better catalytic properties and is the most suitable catalyst for ORR activity.