Steps on Rutile TiO2(110): Active Sites for Water and Methanol   Dissociation
  We present a detailed investigation of the structure and activity of extended defects namely monoatomic steps on (1x1)-TiO2(110). Specifically, the two most stable <001> and <1-11> step edges are considered. Employing an automated genetic algorithm that samples a large number of candidates for each step edge, more stable, reconstructed structures were found for the <1-11> step edge, while the bulk truncated structures were recovered for the <001> step edge. We demonstrate how oxygen vacancies along these defects have lower formation energies than on flat terraces and how water and methanol molecules adsorb dissociatively on reduced <1-11> step edges. Our findings are in agreement with earlier experimental results and indicate an important contribution from step edges to the reactivity of the TiO2(110) surface. 
Umberto Martinez, Lasse B. Vilhelmsen, Henrik H. Kristoffersen, Jess   Stausholm-M{\o}ller and Bj{\o}rk Hammer
cond-mat.mtrl-sci