New surfaces stabilized by adsorbate-induced faceting.
Faceting is a form of self-assembly of single-crystal surfaces at the nanometer-scale in which an initially planar surface converts to a 'hill-and-valley' structure, exposing new faces of low-index surfaces. Our recent studies revealed that, upon annealing in O(2), three-sided nanoscale pyramids form on Ir(210) exposing smooth {311} and partially restructured (110) faces. Through a combination of scanning tunneling microscopy and density functional theory, we identify this structure to be a stepped double-missing-row reconstruction, which is only stable on nanopyramidal facets, not on a planar Ir(110) surface. This faceting-enabled stabilization of a hitherto unstable surface points to a new approach to prepare nanoscale model catalysts for structure-sensitivity studies in heterogeneous (electro-)catalysis with high selectivity and reactivity.
Institut für Elektrochemie, Universität Ulm, Ulm, Germany. payam.kaghazchi@uni-ulm.de
Payam
P
Kaghazchi
Timo
T
Jacob
Ivan
I
Ermanoski
Wenhua
W
Chen
Theodore E
TE
Madey