Catalytic Semihydrogenation of Acetylene on the (100) Surface of the o-Al13Co4 Quasicrystalline Approximant: Density Functional Theory Study

Density functional theory calculations are used to investigate the catalytic properties of the o-Al13Co4(100) surface toward the semihydrogenation of acetylene. The dissociation of the H2 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, H2 dissociation on o-Al13Co4(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.