ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The interaction of CO with a Pd(110) surface has been studied by low energy electron diffraction (LEED), thermal desorption spectroscopy (TDS), and work function measurements (Δφ). c(2×2), (4×1), and (2×1) phases were observed in sequence with increasing CO exposure at 130 K. When the (2×1) phase is heated to ∼330 K, it transforms to the (4×2) phase. At ∼285 K, the phases c(2×2), (4×2), and (2×1) appear in sequence with increasing exposure. The stable final surface configuration at this temperature is the coexistance of the (2×1) and (4×2) phases. The transition (2×1)(arrow-right-and-left)(4×2) is found to be reversible for T≥320 K if the sample is heated and cooled in a CO ambient. The thermal desorption spectra reveal five peaks labeled as α1, α2, α3, β1, and β2, respectively. The sharp α3 peak is found to be associated with the phase transition (2×1)→(4×2) which we believe involves Pd-atom displacements. The desorption of the α3 state CO follows fractional order kinetics (〈0.3). It is also possible that the (4×2) phase involves surface reconstruction. A work function change of 1085±10 mV was measured for a CO saturated surface at 130 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.455225
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