Density functional theory calculation of Ti3C2 MXene monolayer as catalytic support for platinum towards the dehydrogenation of methylcyclohexane

Abstract

The need for sustainable energy systems and reducing greenhouse gas emissions are key drivers in the development of liquid hydrogen organic carriers (LOHCs). Density functional theory calculations were performed on the dehydrogenation of methylocyclohexane (MCH) LOHC to toluene on a Pt (111) and Ti3C2-nPt surface (n = number of layers). The effect of the Ti3C2 MXene monolayer as both a catalyst and catalyst support was evaluated. The Ti3C2 MXene monolayer as the active catalyst for the dehydrogenation of MCH to toluene resulted in negative dehydrogenation energies, whereas the pristine Pt (111) surface has positive dehydrogenation energies. Consideration of the Ti3C2 MXene monolayer as the support for the Pt atoms (Ti3C2-nPt) resulted in positive dehydrogenation energies for the different Pt (111) layers adsorbed on the Ti3C2 MXene monolayer. This implies that the dehydrogenation of MCH would be feasible on both the pristine Pt (111) and Ti3C2-Pt surface at elevated temperatures. The Ti3C2-3Pt heterostructure (3L: three layers), has lower dehydrogenation energies compared to the pristine Pt (111) surface. Thus, the Ti3C2 MXene monolayer enhances the catalytic behaviour of the Pt surface, resulting in improved dehydrogenation of MCH to toluene.