DFT characterization of adsorbed NHx species on Pt(100) and Pt(111) surfaces
authors Novell-Leruth, G; Valcarcel, A; Clotet, A; Ricart, JM; Perez-Ramirez, J
nationality International
journal JOURNAL OF PHYSICAL CHEMISTRY B
keywords INITIO MOLECULAR-DYNAMICS; SELECTIVITY-DIRECTING FACTORS; AMMONIA OXIDATION; AB-INITIO; TEMPORAL ANALYSIS; PRODUCTS REACTOR; BOND STRENGTH; ACTIVE-SITES; PGM GAUZES; ADSORPTION
abstract Periodic density functional theory (DFT) calculations using plane waves have been performed to systematically investigate the adsorption and relative stability of ammonia and its dehydrogenated species on Pt(111) and Pt(100) surfaces. Different adsorption geometries and positions have been studied, and in each case, the equilibrium configuration has been determined by relaxation of the system. The vibrational spectra of the various ammonia fragments have been computed, and band assignments have been compared in detail with available experimental data. The adsorption of NH3 (on top) and NH2 (bridge) is more favorable on Pt(100) than on Pt(111), while similar adsorption energies were computed for NH (hollow) and N (hollow) on both surfaces. The remarkably lower adsorption energy of NH2 over Pt(111) as compared with Pt(100) (the difference being similar to 0.7 eV) can be related to different geometric and electronic factors associated with this particular intermediate. Accordingly, the type of platinum surface determines the most stable NH chi fragment: Pt(100) has more affinity for NH2 species, whereas NH species are preferred over Pt(111).
publisher AMER CHEMICAL SOC
issn 1520-6106
year published 2005
volume 109
issue 38
beginning page 18061
ending page 18069
digital object identifier (doi) 10.1021/jp0516821
web of science category Chemistry, Physical
subject category Chemistry
unique article identifier WOS:000232120900046
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 3.146
5 year journal impact factor 3.101
category normalized journal impact factor percentile 60.204
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg