NO adsorption and thermal behavior on Pd(112): The effect of surface modification by O and Ge

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Langmuir; (United States)

DOI:https://doi.org/10.1021/la00001a030· OSTI ID:6539227

Ramsier, R D; Lee, K W; Yates, Jr, J T ^[1]

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1. Univ. of Pittsburgh, PA (United States)

The effect of O(a) and Ge(a) on the adsorption of NO on the stepped Pd(112) surface has been studied by temperature programmed desorption (TPD), Auger electron spectroscopy (AES), secondary electron emission crystal current (SEECC), low energy electron diffraction (LEED), and electron stimulated desorption ion angular distribution (ESDIAD) methods. The presence of either O or Ge at the Pd(112) surface alters the kinetics of NO thermal desorption, destablizing the NO which subsequently desorbs at lower temperatures. The dissociative NO channels, which produce N[sub 2] and N[sub 2]O as products, are simultaneously suppressed by the preadsorption of O or Ge. The similarities between the NO/O/Pd(112) and NO/Ge/Pd(112) results lead to the conclusion that steric blocking is more important than electronic poisoning effects in these systems. O[sup +] ESDIAD patterns from NO/Pd(112) are essentially identical to those from NO/O/Pd(112) and NO/Ge/Pd(112), implying that the surface modifiers do not preferentially block the step sites toward NO adsorption. The ESDIAD data are interpreted in terms of the random adsorption of O and Ge on the surface. 24 refs., 12 figs.

• OSTI ID: 6539227
• Journal Information: Langmuir; (United States), Journal Name: Langmuir; (United States) Vol. 11:1; ISSN LANGD5; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ADSORPTION
AUGER ELECTRON SPECTROSCOPY
CHALCOGENIDES
COHERENT SCATTERING
DESORPTION
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
GERMANIUM
KINETICS
METALS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PALLADIUM
PLATINUM METALS
SCATTERING
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
THERMAL ANALYSIS
TRANSITION ELEMENTS