Anomalous Dispersion Effects in Diffuse Reflectance Infrared Fourier Transform Spectroscopy: A Study of Optical Geometries

1989 ◽  
Vol 43 (2) ◽  
pp. 267-274 ◽  
Author(s):  
D. M. Hembree ◽  
H. R. Smyrl
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Specular Reflection ◽  
Fourier Transform Spectroscopy ◽  
Anomalous Dispersion ◽  
Fresnel Reflection ◽  
Absorption Bands ◽  
Dispersion Effects ◽  
Diffuse Reflectance Infrared ◽  
Reflectance Measurements

In this report, the two most common diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) optical geometries (on-axis and off-axis) are investigated in terms of adherence to the Kubelka-Munk theory. It was found that specular reflection, whether in the form of regular Fresnel reflection or diffuse Fresnel reflection, is the major cause of spectral distortion in typical diffuse reflectance measurements. A discussion of the origin of the variation in specular background associated with resonances is presented. Once the adverse effects of specular reflection are minimized, the linear relationship between response and concentration predicted by Kubelka-Munk theory was found to extend to concentrated samples. Up to a point, this was the case even for intense absorption bands where anomalous dispersion leads to large changes in specular intensity.

ANALYTICAL APPLICATIONS OF DIFFUSE REFLECTANCE INFRARED FOURIER TRANSFORM SPECTROSCOPY

1982 ◽  
pp. 299-309 ◽  
Author(s):  
Peter R. Griffiths ◽  
S. Agyare Yeboah ◽  
Issam M. Hamadeh ◽  
Pamela J. Duff ◽  
Wang-Jih Yang ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Analytical Applications ◽  
Diffuse Reflectance Infrared

scholarly journals Development of a diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) cell for the in situ analysis of co-electrolysis in a solid oxide cell

2015 ◽  
Vol 182 ◽  
pp. 97-111 ◽  
Author(s):  
Denis J. Cumming ◽  
Christopher Tumilson ◽  
S. F. Rebecca Taylor ◽  
Sarayute Chansai ◽  
Ann V. Call ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Transport Processes ◽  
Solid Oxide ◽  
Electrochemical Measurements ◽  
Ex Situ ◽  
Diffuse Reflectance Infrared ◽  
Solid Oxide Cell

Co-electrolysis of carbon dioxide and steam has been shown to be an efficient way to produce syngas, however further optimisation requires detailed understanding of the complex reactions, transport processes and degradation mechanisms occurring in the solid oxide cell (SOC) during operation. Whilst electrochemical measurements are currently conducted in situ, many analytical techniques can only be used ex situ and may even be destructive to the cell (e.g. SEM imaging of the microstructure). In order to fully understand and characterise co-electrolysis, in situ monitoring of the reactants, products and SOC is necessary. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) is ideal for in situ monitoring of co-electrolysis as both gaseous and adsorbed CO and CO2 species can be detected, however it has previously not been used for this purpose. The challenges of designing an experimental rig which allows optical access alongside electrochemical measurements at high temperature and operates in a dual atmosphere are discussed. The rig developed has thus far been used for symmetric cell testing at temperatures from 450 °C to 600 °C. Under a CO atmosphere, significant changes in spectra were observed even over a simple Au|10Sc1CeSZ|Au SOC. The changes relate to a combination of CO oxidation, the water gas shift reaction, carbonate formation and decomposition processes, with the dominant process being both potential and temperature dependent.

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study of ethyne hydrogenation on Pd/Al2O3

2007 ◽  
Vol 128 (1-2) ◽  
pp. 52-62 ◽  
Author(s):  
J. Wood ◽  
M.J. Alldrick ◽  
J.M. Winterbottom ◽  
E.H. Stitt ◽  
S. Bailey
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Diffuse Reflectance Infrared
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