Design, modelling, and application of a low void-volume in situ diffuse reflectance spectroscopic reaction cell for transient catalytic studies

2019 ◽  
Vol 4 (4) ◽  
pp. 667-678 ◽  
Author(s):  
Bhagyesha S. Patil ◽  
Priya D. Srinivasan ◽  
Ed Atchison ◽  
Hongda Zhu ◽  
Juan J. Bravo-Suárez
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Void Volume ◽  
Sensitive Detection ◽  
Reaction Cell ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation

A new low void-volume in situ reaction cell enables application of modulation excitation-phase sensitive detection-diffuse reflectance Fourier transform spectroscopy (ME-PSD-DRIFTS).

Application of modulation excitation-phase sensitive detection-DRIFTS for in situ/operando characterization of heterogeneous catalysts

2019 ◽  
Vol 4 (5) ◽  
pp. 862-883 ◽  
Author(s):  
Priya D. Srinivasan ◽  
Bhagyesha S. Patil ◽  
Hongda Zhu ◽  
Juan J. Bravo-Suárez
Keyword(s):  
Fourier Transform ◽  
Heterogeneous Catalysts ◽  
Diffuse Reflectance ◽  
Sensitive Detection ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation ◽  
General Method

A new more general method and guidelines for the implementation of modulation excitation-phase sensitive detection-diffuse reflectance Fourier transform spectroscopy (ME-PSD-DRIFTS).

scholarly journals CO2 Methanation over Rh/CeO2 Studied with Infrared Modulation Excitation Spectroscopy and Phase Sensitive Detection

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 601
Author(s):  
Felix Hemmingsson ◽  
Andreas Schaefer ◽  
Magnus Skoglundh ◽  
Per-Anders Carlsson
Keyword(s):  
Reaction Pathway ◽  
Sensitive Detection ◽  
Side Reactions ◽  
Co2 Methanation ◽  
Individual Contributions ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation Spectroscopy ◽  
Modulation Excitation

Methane is a well-established fuel molecule whose production from CO 2 through methanation garners increasing interest as an energy storage solution. While often produced with Ni based catalysts, other metals are of interest thanks to higher robustness and activity-selectivity numbers. The Rh/CeO 2 catalyst has shown appreciable properties for CO 2 methanation and its structural dynamics has been studied in situ. However, the reaction pathway is unknown. Here, we present infrared modulation excitation spectroscopy measurements with phase sensitive detection of a Rh/CeO 2 catalyst adsorbate composition during H 2 pulsing (0–2 vol.%) to a constant CO 2 (0.5 vol.%) feed. Various carbonyl (CO) and carbonate (b-CO 3 /p-CO 3 ) ad-species clearly respond to the hydrogen stimulus, making them potential reaction intermediates. The different CO ad-species are likely intermediates for product CO and CH 4 but their individual contributions to the respective formations are not unambiguously ascertained. As for the carbonate dynamics, it might be linked to the reduction/oxidation of the CeO 2 surface upon H 2 pulsing. Formate (HCOO) ad-species are clearly visible but appear to be, if not spectators, linked to slow side reactions possibly also affected by CeO 2 redox processes.

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.

Temperature control in DRIFT cells used for in situ and operando studies: where do we stand today?

2020 ◽  
Vol 22 (45) ◽  
pp. 26088-26092
Author(s):  
Ignacio Melián-Cabrera
Keyword(s):  
Heat Transfer ◽  
Fourier Transform ◽  
Temperature Control ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Diffuse Reflectance Infrared ◽  
Operando Studies

Heat transfer limitations in diffuse-reflectance-infrared-Fourier-transform-spectroscopy cells, which can affect the measurement in spectrokinetic studies, have been appraised.

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