CO2 Adsorption and Desorption on MgO/Al2O3: An In Situ Diffuse Reflection Infrared Fourier Transform Spectroscopy (DRIFTS) Study

2012 ◽  
Vol 66 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Gengshen Hu ◽  
Lin Zhu ◽  
Aiping Jia ◽  
Xin Hu ◽  
Guanqun Xie ◽  
...  
2012 ◽  
Vol 66 (5) ◽  
pp. 600-605 ◽  
Author(s):  
Gengshen Hu ◽  
Lin Zhu ◽  
Aiping Jia ◽  
Xin Hu ◽  
Guanqun Xie ◽  
...  

The adsorption and desorption of hydrogen on Ir/SiO2 catalyst were studied by using in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) combined with curve-fitting analysis. The results indicate that there are three different surface species formed on the catalyst that correspond to the peaks at 1950, 2010, and 2035 cm−1, respectively, when exposed in H2 flow at 130 °C. These surface species display different adsorption and desorption trends. Surface hydride forms after the catalyst is cooled to 80 °C and it disappears after the catalyst is heated to 130 °C again. This study may help us understand the interaction between hydrogen and noble metals and thus give more insights to heterogeneous catalytic mechanism involving hydrogen and hydrogen storage using metal materials.


2015 ◽  
Vol 182 ◽  
pp. 97-111 ◽  
Author(s):  
Denis J. Cumming ◽  
Christopher Tumilson ◽  
S. F. Rebecca Taylor ◽  
Sarayute Chansai ◽  
Ann V. Call ◽  
...  

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.


2020 ◽  
Vol 22 (45) ◽  
pp. 26088-26092
Author(s):  
Ignacio Melián-Cabrera

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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