Absorption–desorption of carbon dioxide in carbon honeycombs at elevated temperatures
Nina V. Krainyukova1, Yuri Bogdanov1,2, and Bogdan Kuchta3,4
1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
2National Technical University “Kharkiv Polytechnical Institute”, 2 Kyrpychova Str., Kharkiv 61002, Ukraine
3Université Aix-Marseille, CNRS, MADIREL, Marseille 13396, France
4Department of Physics and Astronomy, University of Missouri, Columbia MO, USA
Received October 24, 2018
The recently synthesized honeycomb carbon allotrope has numerous potential applications, in particular for storage of gases inside carbon matrices. In this work this carbon form was experimentally studied in its denser form in order to estimate the upper temperature limit for keeping a gas inside the cellular structure. Along with the previously reported random honeycombs of a zigzag type we have also revealed the densest armchair structure. The mechanism of absorption–desorption of carbon dioxide studied by means of high energy electron diffraction at low temperatures showed the two — stage character of the observed desorption at elevated temperatures. This effect is associated to the weaker or stronger bonding of molecules with pore walls depending on the specific configuration of channels with different sizes. We have found that complete desorption of CO2 does not occur even at the temperatures about three times higher as compared with the sublimation point of carbon dioxide in our vacuum conditions.
Key words: high-energy electron diffraction, gas absorption, carbon honeycombs.