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Title: Nitrogen-induced reconstruction and faceting of Re(112{sup ¯}1)

The surface morphology of Re(112{sup ¯}1), tailored on the nanometer scale by kinetic control of nitrogen, has been investigated using low energy electron diffraction, scanning tunneling microscopy, Auger electron spectroscopy, and density functional theory (DFT) in combination with the ab initio atomistic thermodynamics approach. Experiments show that when exposing to NH{sub 3} (>0.5 L) at 300 K followed by annealing in ultra-high vacuum at 700 K or 900 K, the initially planar Re(112{sup ¯}1) surface becomes (2 × 1) reconstructed or partially faceted, respectively. Upon annealing in 100 L NH{sub 3} at 900 K, Re(112{sup ¯}1) becomes fully faceted and covered by N. The fully faceted surface consists of two-sided ridges formed by (134{sup ¯}2) and (314{sup ¯}2) facets. The (2 × 1) reconstruction may serve as a precursor state for faceting of Re(112{sup ¯}1). The DFT calculations provide an atomistic understanding of facet formation in terms of binding sites and energies of N on Re surfaces of the substrate and facets as well as the corresponding surface phase diagram. The N-covered faceted Re(112{sup ¯}1) surfaces are promising nanoscale model catalysts and nanotemplates. Our findings should be of importance for the design and development of Re-based heterogeneous catalysts operating undermore » nitrogen-rich conditions.« less
Authors:
; ;  [1] ; ;  [2]
  1. Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States)
  2. Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89069 Ulm (Germany)
Publication Date:
OSTI Identifier:
22253606
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY; AMMONIA; ANNEALING; AUGER ELECTRON SPECTROSCOPY; CATALYSTS; CONTROL; DENSITY FUNCTIONAL METHOD; ELECTRON DIFFRACTION; NANOSTRUCTURES; NITROGEN; PHASE DIAGRAMS; PRECURSOR; SCANNING TUNNELING MICROSCOPY; SUBSTRATES; SURFACES; THERMODYNAMICS