In-situ Fourier transform infrared

In situ Fourier transform infrared and in situ infrared reflection spectroscopies have been used to study the electrical double layer structure and adsorption of various species at low-index single-crystal faces of Au, Pt, and other electrodes.206"210 It has been shown that if the ions in the solution have vibrational bands, it is possible to relate their excess density to the experimentally observed surface. 

Faguy PW, Markovic N, Adzic RR, Fierro C, Yeager E. 1990. A study of bisulfate adsorption on Pt(lll) single crystal electrodes using in-situ Fourier transform infrared spectroscopy. J Electroanal Chem 289 245 -262. 

We have found new CO-tolerant catalysts by alloying Pt with a second, nonprecious, metal (Pt-Fe, Pt-Co, Pt-Ni, etc.) [Fujino, 1996 Watanabe et al., 1999 Igarashi et al., 2001]. In this section, we demonstrate the properties of these new alloy catalysts together with Pt-Ru alloy, based on voltammetric measurements, electrochemical quartz crystal microbalance (EQCM), electrochemical scanning tunneling microscopy (EC-STM), in situ Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). 

Figure 10.6. In situ Fourier transform infrared spectra of decane SCR-NO in the presence and absence of hydrogen on Ag/Al203 at 200°C. Evolution of intensities of the bands characteristic for adsorbed species (monodentate nitrates 1245 cm-1, bidentate nitrates 1295 cm-1, —CN 2150 cm-1 and —NCO 2230 cm-1. 1000 ppm NO, 6vol.%02,750 ppm decane, Oor 1000 ppm H2 (reproduced with permission from Ref. [12]).

In-situ Fourier transform infrared spectroscopy. The final technique in this section concerns the FTIR approach which is based quite simply on the far greater throughput and speed of an FTIR spectrometer compared to a dispersive instrument. In situ FTIR has several acronyms depending on the exact method used. In general, as in the EMIRS technique, the FTIR-... 

These assumptions are partially different from those introduced in our previous model.10 In that work, in fact, in order to simplify the kinetic description, we assumed that all the steps involved in the formation of both the chain growth monomer CH2 and water (i.e., Equations 16.3 and 16.4a to 16.4e) were a series of irreversible and consecutive steps. Under this assumption, it was possible to describe the rate of the overall CO conversion process by means of a single rate equation. Nevertheless, from a physical point of view, this hypothesis implies that the surface concentration of the molecular adsorbed CO is nil, with the rate of formation of this species equal to the rate of consumption. However, recent in situ Fourier transform infrared (FT-IR) studies carried out on the same catalyst adopted in this work, at the typical reaction temperature and in an atmosphere composed by H2 and CO, revealed the presence of a significant amount of molecular CO adsorbed on the catalysts surface.17 For these reasons, in the present work, the hypothesis of the irreversible molecular CO adsorption has been removed. 

In 1993, Blatter and Frei [34] extended the Aronovitch and Mazur [28] photo-oxidation into zeolitic media, which resulted in several distinctive advantages as described below. Irradiation in the visible region (633 nm) of zeolite NaY loaded with 2,3-dimethyl-2-butene, 16, and oxygen resulted in formation of allylic hydroperoxide, 17, and a small amount of acetone. The reaction was followed by in situ Fourier-transform infrared (FTlR) spectroscopy and the products were identified by comparison to authentic samples. The allylic hydroperoxide was stable at - 50°C but decomposed when the zeolite sample was warmed to 20°C [35]. In order to rationalize these observations, it was suggested that absorption of light by an alkene/Oi charge-transfer complex resulted in electron transfer to give an alkene radical cation-superoxide ion pair which collapses... 

Hug, S.J. (1997) In situ Fourier transform infrared measurements of sulfate adsorption on hematite in aqueous solutions. J. Colloid Interface Sci. 188 415-422 Hug, S.J. Canonica, L. Wegelen, M. Gechter, D. vonGrunten, U. (2001) Solar oxidation and removal of arsenic at circumneutral pH in iron containing waters. Environ. Sci. Techn. 35 2114-2121... 

The adsorption and reduction of N03 ions at Au and Pt electrodes was studied by in situ fourier transform infrared (FTIR) spectroscopy [55]. Possible adsorption geometries were suggested for adsorbed nitrate ions and for nitrite ions formed by reduction. 

For instance, in situ Fourier transform infrared (FTIR) spectroscopy has been used by Faguy etal. [176] to study the potential-dependent changes in anion structure and composition at the surface of Pt(lll) electrodes in H 804 -containing solutions. From the infrared differential normalized relative reflectance data, the maximum rate of intensity changes for three infrared bands can be obtained. Two modes associated with the adsorbed anion... 

Oxidation of thiourea adsorbed on Au(lll) and pc-Au electrode in 0.1 M HCIO4 has been investigated using CV, in situ Fourier transform infrared spectroscopy, and differential electrochemical mass spectrometry [165]. Two reaction mechanisms were proposed for the oxidation of the adsorbed and nonadsorbed thiourea. For both types of Au electrodes, similar results were obtained. 

The ILs interact with surfaces and electrodes [23-25], and many more studies have been done that what we can cite. As one example, in situ Fourier-transform infrared reflection absorption spectroscopy (FT-IRAS) has been utilized to study the molecular structure of the electrified interphase between a l-ethyl-3-methylimidazolium tetrafluoroborate [C2Qlm][BF4] liquid and gold substrates [26]. Similar results have been obtained by surface-enhanced Raman scattering (SERS) for [C4Cilm][PFg] adsorbed on silver [24,27] and quartz [28]. 

Chen, Y. Zhou, G.X. Brown, N. etal., Study of lactol activation by trifluoroacetic anhydride via in situ Fourier transform infrared spectroscopy Anal. Chim. Acta 2003, 497, 155-164. 

Although they may be part of a catalyst testing [1-3] programme, investigations focused on revealing the reaction mechanism, such as in-situ Fourier transform infrared (FTIR) in transmission or reflection mode, nuclear magnetic resonance (NMR), X-ray diffraction (XRD), X-ray absorption fine-structure spectroscopy (EXAFS), X-ray photoelectron spectroscopy (XPS), electron microscopy (EM), electron spin resonance (ESR), and UV-visible (UV-vis) and the reaction cells used are not included. For the correct interpretation of the results, however, this chapter may also provide a worthwhile guide. 

In-Situ Fourier Transform Infrared Spectroscopy A Tool to Characterize the Metal-Electrolyte Interface at a Molecular Level... 

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