scholarly journals Problems of metrological assurance of gas analysis using IR spectroscopy

Author(s):  
Leonid Konopelko ◽  
Vitaly Beloborodov ◽  
Dmitry Rumiantsev ◽  
Ian Chubchenko

The survey article presents the results of work on metrological assurance of measurements using IR spectrometers, IR correlation gas analyzers and CRDS instruments. For the successful application of the existing databases in absorption spectroscopy, it is necessary to identify the most accurate data and assign uncertainty to it, based on experimental studies using reference gas mixtures. The properties of the methods that lead to a deterioration in the measurement accuracy were investigated and the ways were suggested to overcome the shortcomings of the measuring methods.

2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.


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