Adsorption of thiophene on Ni(1 0 0), Cu(1 0 0), and Pd(1 0 0) surfaces: ab initio periodic density functional study

Adsorption of thiophene on the (1 0 0) surfaces of Ni, Cu, and Pd has been investigated by the ab initio density functional theory method (periodic DMol3). Several parallel and perpendicular adsorption geometries are examined in detail. For Ni(1 0 0), both dissociative and molecular adsorption structures are found with small difference in energy. Thiophene adsorbs only molecularly on Cu(1 0 0) and Pd(1 0 0). The most stable molecular adsorption structures on all the surfaces are quite similar, where thiophene adsorbs on top of a 4-fold hollow with the symmetry axis rotated 45° from the metal rows. These stable structures arise from a good matching of the thiophene molecule to the metal surfaces. The calculated adsorption geometries are in reasonable agreement with XAFS experiments.