First principles computational investigation on the possibility of Pt-decorated SiC hexagonal sheet as a suitable material for oxygen reduction reaction

Abstract

First principles calculations play a significant role in developing and optimizing new energy storage and conversion materials especially at the nanoscale. In this work, the structural, energetics and, electronic properties of adsorbed Pt atom onto two-dimensional graphene, hexagonal BN (h-BN) and SiC (h-SiC) sheets have been investigated at DFT–B3LYP level of theory using coronene molecule as a suitable model. Spin-polarization and model size effects on the Pt adsorption properties have also been evaluated. Various positions for establishing Pt atom on the selected substrates have been considered and full structural optimization was carried out for all selected systems. The adsorption energies, electronic structures and charge population analysis indicated that in all the studied structures there were strong interaction between two interacting entities. It was also found that the adsorption ability of h-SiC is much stronger than the other counterparts with adsorption energy of −3.828eV.We have also examined the O2 adsorption properties of Pt-decorated graphene, h-BN and h-SiC sheets for possible tunability of O2 adsorption strength of systems under study. We found that h-SiC sheet possess a weakened O2 adsorption energy among the selected substrates. In view of the strong stability of adsorbed Pt atom on h-SiC sheet and relatively weaker O2 adsorption energy, one can expect that h-SiC might be a promising material for support assistant as well as increasing the catalytic activity of Pt atoms compared to graphene and h-BN substrates. This may attribute to preventing aggregating of Pt atoms due to the strong fastening nature of the h-SiC sheet and also by affording a balance in the O2 adsorption strength that lead to enhanced catalyst turnover. Therefore, our first principles findings offer a unique opportunity for design and applications of SiC-based nanoscale supports in fuel cell technology.