Polarization-modulation infrared reflection absorption spectroscopy (PM-IRAS) is used to study CO adsorption on AuPd(100) surfaces, one well-annealed such that contiguous Pd sites do not initially exist and a second ion sputtered such that contiguous Pd sites are exposed. At CO pressures e1 × 10-3 Torr, Pd segregation to the surface is found; however, it is not sufficient to form contiguous Pd ...

between measured CDAD spectra and calculated values for spatially oriented CO and NiCO clearly confirms the well-known perpendicular adsorption for CO on Ni(100), whereas for CO adsorbed on Fe(100) a tilted adsorption geometry was found. For NO/Ni(100) and for NO on the oxygenpreadsorbed Ni(100) surface, an average tilt angle of Q. =40+10' was observed. In the case of the oxygen-preadsorbed Ni(...

Kinetic, isotopic, and infrared studies on well-defined dispersed Pt clusters are combined here with first-principle theoretical methods on model cluster surfaces to probe the mechanism and structural requirements for CO oxidation catalysis at conditions typical of its industrial practice. CO oxidation turnover rates and the dynamics and thermodynamics of adsorption-desorption processes on clus...

The energetics of elementary surface processes relevant for CO oxidation, particularly CO and O2 adsorption, were investigated by a direct calorimetric method on model Pd nanoparticles and on the extended Pd(111) single crystal surface. The focus of this study lies on a detailed understanding of how a nanometer scale confinement of matter affects the binding strength of gaseous adsorbates. We r...

Abstract. Pb/Ni(111) surface phases were investigated by synchrotron radiation photoemission, low-energy electron diffraction (LEED) and angular resolved ultraviolet photoelectron spectroscopy (ARUPS). For room temperature evaporation, two surface ordered layers, (3x3) and (4x4), were observed. The Pb 5d and Pb 4f core levels as well as valence band spectra indicated a weak chemical interaction...

The IR spectra of adsorbed CO and NO probe molecules were used to characterize the coordination chemistry of Fe(2+) ions in solution ion exchanged Fe,H/SSZ-13 zeolites. The effects of Fe ion exchange levels, as well as the sample pre-treatment conditions, on the adsorption of these probe molecules were investigated. The ion exchange levels (in the range of the study) did not affect significantl...

In situ soft X-ray absorption spectroscopy (XAS) was employed to study the adsorption and dissociation of carbon monoxide molecules on cobalt nanoparticles with sizes ranging from 4 to 15 nm. The majority of CO molecules adsorb molecularly on the surface of the nanoparticles, but some undergo dissociative adsorption, leading to oxide species on the surface of the nanoparticles. We found that th...

Infrared reflection absorption spectroscopy (IRAS) was used to study the adsorption of carbon monoxide on mixed S and Co overlayers on a Mo(l10) surface. The results of this study indicate that there is a migration/ segregation of the adatoms into 2-D and 3-D islands and that the different domains are distinguishable by the stretching frequency of the adsorbed CO. Clean Mo(l10) as well as sulfi...

In situ FT-IR spectroscopy was exploited to study the adsorption of CO2 and CO on commercially available yttria-stabilized ZrO2 (8 mol % Y, YSZ-8), Y2O3, and ZrO2. All three oxides were pretreated at high temperatures (1173 K) in air, which leads to effective dehydroxylation of pure ZrO2. Both Y2O3 and YSZ-8 show a much higher reactivity toward CO and CO2 adsorption than ZrO2 because of more fa...

The preparation and characterization of high-surface-area polymeric substrates suitable for the microcalorimetry of protein adsorption are described. High-surface-area polystyrene, poly(styrene-co-butyl methacrylate) and poly(styrene-co-allyl alcohol) were prepared by adsorbing polymer from solution onto fumed silica. Verification of adsorption of polystyrene by silica was determined by noting ...