Highly efficient solid state catalysis by reconstructed (001) Ceria surface

Substrate engineering is a key factor in thesynthesis of new complex materials. The substrate surface has to be conditioned in order to minimized the energy threshold for formation of the desired phase, or, to enhance catalytic activity of the substrate. Here we explore (001) surface structure of CeO2 which is well known catalytically active material. The surface is created by heat treating small-grain CeO2 films with terminated with (111) facets in a controlled atmosphere. This process yields several distinct and stable (001) surface reconstructions. The reconstructed substrates are used to grow epitaxial film of a high-temperature superconductor YBa2Cu3O7. The film grown on the substrate having the longest, 4-fold period reconstruction exhibits a twofold increase in performance over surfaces with shorte period reconstructions. This is explained by the cross over between the nucleation site dimensions and the period of the surface reconstruction. This result opens a new avenue for catalysis mediated solid state synthesis.