Physico-Chemical nanomaterials science

Bromination and amination of nanoporous activated carbon

Grishchenko L.M.1, Diyuk V.E.1 , Zaderko A.N.1, Novychenko N.S.2, Mischanchuk O.V.3, and Lisnyak V.V.1

1Taras Shevchenko National University of Kyiv, Volodymyrska Street 64/13, Kyiv 01601, Ukraine. E-mail: liudmyla.grishchenko@gmail.com

2M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Kyiv 01004, Ukraine.

3O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, Kyiv 03164, Ukraine.

Nanoporous activated carbon (AC) has widely used for adsorption and catalysis owing to the developed porous structure and chemical resistance in different media. For such requirements, the knowledge on the surface reaction of carbon is an important task. In contrast to oxygen-containing surface groups, by chemical functionalization of AC surface with Hal-, N-, and S-containing groups one can change the acid-base properties in a wide pH range. The grafted specific groups can act as more effective sites for metal ions adsorption and uptake of metal-complexes. We devoted the current study to the reactions of AC with bromine and investigated the surface and thermal behavior of the resulting halogen-containing AC. We also consider the possibility to use synthesized halogen-containing precursors for producing nitrogen-containing ACs. As the initial starting material, we chose synthetic nanoporous AC obtained by pyrolysis of vinyl pyridine polymer and followed activation of the pyrolysis product. Bromination of AC is carried out using liquid bromine and an aqueous solution of bromine in potassium bromide. The substitution of bromine groups with amino groups was carried out in alcoholic solutions of amines, by heating for 10 h. The obtained samples were studied by TPD MS, TGA, TPD IR, and SEM methods. In the brominated AC, the bromine content is about 0.45 mmol/g and showed no prominent dependence from the used synthetic method. Subsequent treatment with amines leads to the grafting of amino groups onto the surface. This amino groups’ content ranged from 0.3 to 0.7 mmol/g. The obtained samples can be used as adsorbents and catalyst carriers for the supporting of noble metals in the catalytic oxidation of small molecules [1].

[1]. Radkevich V.Z., Senko T.L., Wilson K., Grishenko L.M., Zaderko A.N. Diyuk V.Y. The influence of surface functionalization of activated carbon on palladium dispersion and catalytic activity in hydrogen oxidation // Appl. Catal., A.-2008.-335, N 2.-P.241-251.