IR reflection-absorption spectroscopy IRAS

The IR and Raman spectra of benzotriazole, benzotriazole anion and its Cu(I) complex have been measured. The characteristic peaks in the IR spectrum of the triazole moiety in benzotriazole anion occur at 1163 cm , 1134 cm , and 1115 cm . A broad band with a main peak at 1151 cm occurs in the spectrum of the Cu(I)-BTA complex <85JST(l00)57i>. The chemisorption of benzotriazole on clean copper and cuprous oxide surfaces is investigated by combining XPS, UV-PE and IR reflection absorption spectroscopy (IRAS). Coordination geometry including the triazole-... 

The issue of various adsorption sites featured by supported Pd nanoparticles was also dealt with in our work [256]. There, the adsorption of CO on nanosize Pd particles was studied theoretically by a DF method (BP86) and spectroscopically by means of IR reflection absorption spectroscopy (IRAS) and sum frequency generation (SFG). Three-dimensional crystallites of about 140 atoms (chosen as fragments of fee Pd bulk as justified above), that exhibit (111) and (001) facets, were studied in GGA BP86 calculations. Various types of adsorption sites were inspected three-fold hollow, bridge, and on-top positions at... 

In situ studies of catalytic reactions have also been a prime focus of our group. The high-pressure spectroscopic technique used in our research is polarization modulation IR reflection absorption spectroscopy (PM-IRAS). Like SFG, PM-IRAS is a highly surface-sensitive technique that yields vibrational information about adsorbed surface species. Unlike SFG, however, PM-IRAS... 

Poiarization-Modulation IR Reflection Absorption Spectroscopy (PM-IRAS) High-pressure X-ray Photoeiectron Spectroscopy (HP-XPS)... 

First, surface-sensitive techniques that can operate under technologically relevant conditions, i.e., at least in the 1 —lOOOmbar pressure range, are required. In this respect, photon-based techniques such as sum frequency generation (SFG) and polarization-modulation IR reflection absorption spectroscopy (PM-IRAS) provide surface vibrational spectra of adsorbates from UHV up to atmospheric pressure. Although electron spectroscopies are typically limited to pressures <10 mbar, recent developments in XPS allow the determination of... 

Fig. 10. Schematic illustration of polarization-modulated IR reflection absorption spectroscopy (PM-IRAS).

RAIRSReneclion-absorplion infrared. spectroscopy (or IRAS IR reflection-absorption spectroscopy)... 

Reflection-Absorption IR spectroscopy (RAIRS) where the linearly polarized IR beam is specularly reflected from the front face of a highly reflective sample, such as a metal single crystal surface (Figure 3.1(a)). This is also sometimes referred to as IRAS (IR reflection absorption). The IR beam comes in at grazing angle (i.e. almost parallel to the surface), and although absorption bands in RAIRS have intensities that are some two orders of magnitude weaker than in transmission studies on... 

One of the most commonly applied IR techniques developed to overcome these problems is the external reflectance technique. In this method, the shong solvent absorption is minimized by simply pressing a reflective working electrode against the IR transparent window of the electrochemical cell. The sensitivity problem, that is, the enhancement of the signal/noise ratio in the case of external reflectance techniques is solved by various approaches. These are, for instance, electrochemically modulated infrared spectroscopy (EMIRS), in situ FTIR (which use potential modulation), and polarization modulation infrared reflection absorption spectroscopy (PM-IRAS, FTIR) [86,117-123]. 

With these favorable circumstances, the HREEL spectrum of poiyimide reveals a large number of vibrational bands, quite well resolved from each other. In order to help band assignments, IR transmission spectrum, or Fourier Transform IRAS (Infrared Reflection Absorption Spectroscopy) spectra, from model ODA, PMDA and PMDA-ODA surfaces can be used. These last spectral data have been superimposed on the HREEL spectrum, in the 1000-2(XX) cm i region, where a number of vibrational bands do signiflcandy overlap (Fig. 2). It is quite clear that all the different chemical sites have their fingerprints t... 

Itmumerable mechanistic studies of alcohol oxidation on Pt-based electrocatalysts in acidic media have been published over the last few years. Methanol, " ethanol ° and ethylene glycol have been the most studied substrates and their oxidation paths on Pt or Pt alloys have been substantiated using a variety of in situ, extra situ and operando techniques as well as quantum mechanical calculations. The experimental techniques include reflection IR spectroscopy (IR), surface enhanced IR asbsorption spectroscopy (SEIRAS), " attemrated total reflection-IR absorption spectroscopy (ATR-IRAS), differential electrochemical mass spectroscopy (DEMS), single potential alteration IR spectroscopy... 

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