Nanostructured Surface

From destructive adsorption of CCl4 to bonding sulphogroups onto nanoporous activated carbon fibers
Grishchenko L.M.1, Vakaliuk A.V.1, Diyuk V.E.1, 
Mischanchuk O.V.2, Boldyrieva O.Yu.1, Bezugla T.M.1, and Lisnyak V.V.1
1 Faculty of Chemistry, Taras Shevchenko National University of Kyiv. Volodymyrska Str., 64, Kyiv-01601, Ukraine. 
E-mail: liudmyla.grishchenko@gmail.com
2 O.O. Chuiko Institute of Surface Chemistry of NAS of Ukraine, Gen. Naumova Prosp., 17, Kyiv-03164, Ukraine 

Activated carbons (ACs) are currently the standard adsorbents in respirators against chlorinated hydrocarbons gases and vapors, since they had sufficient surface area and pore volume to warrant such consideration. The effective adsorption of CCl4 molecules was also observed on pitch-based activated carbon fiber (ACF). According to foresee that conducted within the framework of Kierlik-Rosinberg's DFT method simulations, one could achieve the separation of CCl4 molecules from the air if use the AC adsorbents with a pore size of 1.39 nm. However, to transform the resulted adsorbent into the dehydration catalysts, nanoporous Busofit© activated carbon fibers (BACFs) were functionalized with 2.50 mmol×g–1 of chlorine, presumably, in the form of trichlorocarben –CCl3 and chlorine –Cl groups, by using a Ar/CCl4 flow at 450 °С. About 1.1–1.4 mmol×g–1 of chlorine of the grafted groups was substituted with SO3H groups by a wet route combining sulfidation, oxidation and hydrolysis stages [1]. Surface chemistry of sulfonated pre-chloralkylated BACFs was examined by TPD-MS and TPD-IR methods of analysis. These solids have high catalytic performance in the propan-2-ol dehydration to propene; up to 100% conversion can be reached at 215–220 °С. The pyrolitic chlorinatioin/chloralkylation caused the highest thermal stability of grafted groups, so, the resulted sulfonated ACFs can be used repeatedly in the dehydration reaction.

1.	Bezugla T.M., Grishchenko L.M. et al. Covalent bonding of sulfogroups to activated carbon fibers: The role of bromine plasma pretreatment. // Mol Cryst Liq Cryst.-2018.-661.-P. 58-67.