Doped Graphene as a Material for Oxygen Reduction Reaction in Hydrogen Fuel Cells: A Computational Study

Abstract

Because of its high specific surface area and unique electronic properties, graphene with substitutional impurity metal atoms and clusters attached to defects in the graphene sheet is attractive for use in hydrogen fuel cells for oxygen reduction at the cathode. In an attempt to find a cheap yet efficient catalyst for the reaction, we use density-functional theory calculations to study the structure and properties of transition-metal-vacancy complexes in graphene. We calculate formation energies of the complexes, which are directly related to their stability, along with oxygen and water adsorption energies. In addition to metals, we also consider nonmetal impurities like B, P, and Si, which form strong bonds with under-coordinated carbon atoms at defects in graphene. Our results indicate that single Ni, Pd, Pt, Sn, and P atoms embedded into divacancies in graphene are promising candidates for the use in fuel cell cathodes for oxygen reduction reaction (ORR). We further discuss how ion irradiation of graphene combined with metal sputtering and codeposition can be used to make an efficient and relatively inexpensive graphene-based material for hydrogen fuel cells.

Sn-embedded graphene: An active catalyst for CO oxidation to CO 2 ?

“…But generally, the interaction between molecules and the pristine graphene is relatively weak due to the strong sp 2 binding between carbon atoms in the graphene sheet. On the other hand, functionalization and doping are known to modify the chemical properties of graphene sheets to improve their response to gases [9][10][11][12][13][14]. In particular, doping with metal adatoms seems to be even more interesting due to the inherent diversity of their chemical properties [15,16].…”

Computational chemistry for graphene-based energy applications: progress and challenges

“…These authors attempted to explain the experimentally-observed catalytic behaviour of these materials on the basis of calculated electron spin densities in the vicinity of the dopant sites. A comprehensive and rigourous set of graphene dopant screening calculations (using PW-DFT with the Perdew functional) were reported by Kaukonen et al 204 , for both single and double doping sites. These authors targeted both the formation energy of the doped structure, and the O 2 adsorption energy, as their key metrics for evaluating the suitability of each candidate catalyst material.…”

Propiedades catalíticas de grafeno dopado con metales de transición

“…Por sus propiedades únicas, tales como elevada área superficial específica, movilidad de electrones de alta velocidad a temperatura ambiente, excelente conductividad térmica y extraordinarias propiedades mecánicas [1,2,3], ha atraído la atención de diferentes áreas de investigación, en particular la electrocatálisis.…”