Catalytic Semihydrogenation of Acetylene on the (100) Surface of the o-Al 13 Co 4 Quasicrystalline Approximant: Density Functional Theory Study

Density functional theory calculations are used to investigate the catalytic properties of the o-Al 13 Co 4 (100) surface toward the semihydrogenation of acetylene. The dissociation of the H 2 molecule is the key process in this case, since the surface termination does not contain protruding Co atoms, according to a combination of surface science studies and ab initio calculations. However, compared to the pure Al(100) and Al(111) surfaces, H 2 dissociation on o-Al 13 Co 4 (100) proceeds much easier, due to the presence of surface Co atoms slightly below the mean position of the termination plane. A possible mechanism for the hydrogenation is presented, highlighting the selectivity of the reaction on this Al-rich surface.