Carbon dioxide adsorption and activation on ionic liquid decorated Au(111) surface: A DFT study.

We use first principle approaches to study the adsorption and catalytic activation mechanism of CO on ionic liquids (ILs, [CMIm][Cl] (n = 0-6)) attached to a Au(111) surface. The adsorption of CO at this liquid-solid model interface occurs via either (i) parallel π-stacking mode or (ii) CO oxygen lone pair (lp)···π interaction. These CO physisorption modes, which depend on the CO landing angle at this interface, are identified as an efficient way to activate CO and its further conversion into value-added products. For illustration, we discuss the conversion of CO into formic acid where the ILs@Au(111) decorated interface allows reduction of the activation energy for the CO + H → HCOOH reaction. In sum, our electrode/electrolyte based interface model provides valuable information to design novel heterogeneous catalysts for CO conversion. Indeed, our work establishes that a suitable interface material is enough to activate CO.