Nanocomposites and nanomaterials

Catalysts based on chlorinated carbon fibers for dehydration of isopropyl alcohol 
Grishchenko L.M.1, Bezugla T.M.1, Vakaliuk A.V.1, Tsapyuk G.G.1, 
Mischanchuk O.V.2, Boldyrieva O.Yu1, Diyuk V.E.1
1Taras Shevchenko National University of Kyiv, Volodymyrska Street, 64/13, Kyiv -01601, Ukraine, E-mail: liudmyla.grishchenko@gmail.com
2O.O. Chuiko Institute of Surface Chemistry of the NAS of Ukraine, Generala Naumova, 17, Kyiv-03164, Ukraine

Carbon nanomaterials have unique properties, which are determined by their surface chemistry and developed porous structure. They are widely used as fillers for composite materials, microporous adsorbents, including for medical purposes, as well as carriers of catalysts for organic synthesis [1]. Today is crucial to develop methods for the targeted surface modification of carbon materials. These methods will open ways for creating adsorbents with high selectivity, specific carriers of catalysts, and catalysts with a developed surface [2].
This work is devoted to the study of chlorination of carbon PAN fibers, and the resulting chlorine-containing precursors will be used to obtain sulfur-containing PAN fibers. Chlorination was performed with carbon tetrachloride at the temperature of 300, 450, and 600 °C under an argon atmosphere. It was found that the concentration of chlorine in the modified samples depends on the chlorination temperature. The chlorine concentration takes a value of up to 1.7 mmol/g. The substitution of active chlorine by sulfur-containing groups was performed in sodium sulfide and mercaptoacetate solutions. We found by the TPD MS method that the thermal destruction of the surface layer of sulfonated PAN samples occurs with the release of SO2 in the temperature range 170–500 °C. It is shown that the obtained sulfur-containing catalysts have high activity in the dehydration reaction of isopropyl alcohol. The reaction temperatures over the sulfur-containing carbon fibers are low, being for the most active samples in the range up to 220 °C.

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