Carbon dioxide molecular interactions with hydrogenated Ni(111) surface: a DFT study

Within the density functional theory (DFT) study, we considered the contact of carbon dioxide (CO2) with the hydrogenated Ni(111) surface covered with adsorbed hydrogen. The hydrogenation of CO2 over the Ni(111) surface causes the formation of [HC(OH)(2)], [COOH], [HCOO], and [C(OH)(2)] reaction intermediates confirmed by the present DFT investigation. The formation of the [HC(OH)(2)] and [C(OH)(2)] intermediates is observed for the first time. When CO2 has approached the on-top Ni site on a partially hydrogen-covered Ni(111) surface, the [COOH] intermediate is successfully formed. Hydrogen adsorption is a reason for an increase in the CO2 adsorption energy compared to that of the CO2 adsorbed on the clean Ni(111) surface. Our results can help understand the CO2 adsorption on the nanoscale Ni metal. They will be useful in guiding experiments in developing better nanomaterials for efficient gas sensing.