CO 2 Adsorption on PtCu Sub-Nanoclusters Deposited on Pyridinic N-Doped Graphene: A DFT Investigation.

To reduce the CO 2 concentration in the atmosphere, its conversion to different value-added chemicals plays a very important role. Nevertheless, the stable nature of this molecule limits its conversion. Therefore, the design of highly efficient and selective catalysts for the conversion of CO 2 to value-added chemicals is required. Hence, in this work, the CO 2 adsorption on Pt 4-x Cu x (x = 0-4) sub-nanoclusters deposited on pyridinic N-doped graphene (PNG) was studied using the density functional theory. First, the stability of Pt 4-x Cu x (x = 0-4) sub-nanoclusters supported on PNG was analyzed. Subsequently, the CO 2 adsorption on Pt 4-x Cu x (x = 0-4) sub-nanoclusters deposited on PNG was computed. According to the binding energies of the Pt 4-x Cu x (x = 0-4) sub-nanoclusters on PNG, it was observed that PNG is a good material to stabilize the Pt 4-x Cu x (x = 0-4) sub-nanoclusters. In addition, charge transfer occurred from Pt 4-x Cu x (x = 0-4) sub-nanoclusters to the PNG. When the CO 2 molecule was adsorbed on the Pt 4-x Cu x (x = 0-4) sub-nanoclusters supported on the PNG, the CO 2 underwent a bond length elongation and variations in what bending angle is concerned. In addition, the charge transfer from Pt 4-x Cu x (x = 0-4) sub-nanoclusters supported on PNG to the CO 2 molecule was observed, which suggests the activation of the CO 2 molecule. These results proved that Pt 4-x Cu x (x = 0-4) sub-nanoclusters supported on PNG are adequate candidates for CO 2 adsorption and activation.