Structure and Electrocatalytic Activity of Aniline-formaldehyde Polymer Doped with Copper(II) Chloride

Abstract

Copper-containing composites ofaniline-formaldehyde polymer (AFP) are prepared by introduction of CuCl 2 in situ of polycondensation of aniline with formaldehyde and by the impregnating method. Theinfluence of synthesis conditions on phase structure, copper content and electrocatalytic activity of the composites is investigated. The presence of copper oxides (CuO, Cu 2 O) and 2CuCl 2 ·5Cu(OH) 2 ·H 2 O complex compoundis determinedby XRD analysis in composites obtained by the first and second method, respectively. AFP + CuCl 2 composites are tested on electrocatalytic activity in electrohydrogenation of onitroaniline. It is shown that composites prepared by the impregnating method possess higher activity as electrocatalysts in this process.The incorporation of metal-containing inorganic compounds (oxides, hydroxides, metal salts and their nanoparticles) into polymeric matrix allows the obtaining of new composites possessing the specific physicochemical properties: optical, conductive, magnetic, catalytic, etc. [1,2] Various polymers with functional groups in their structure are able to interact with molecules of these compounds and by the way to stabilize their nanoparticles. The structure of aniline-formaldehyde (AF) polymers contains amino groups possessing strong ability to the coordination coupling with atoms and metal ions, therefore it is possible to produce the polymer-metal composites with various properties on the basis of these AF-polymers.Aniline-formaldehyde polymers (or resins) are thermoreactive or thermoplastic products of aniline and formaldehyde interaction. [3] The cured AF-resins are resistant to effect of water, alkalis, oils, but they are decomposed by strong acids. As for electrical insulation properties they are outperform the melamine-, urea-and phenol-formaldehyde resins. AF-polymers are wide used in production of electrotechnical plastics and components for radio-and high-frequency electrical engineer-ing. They are successfully applied as chemically resistant materials in different alkaline solutions.As is evident from the literary search, to produce metal-aniline-formaldehyde composites the impregnating method (or more exactly the method of metal cations sorption with AFpolymers from aqueous solution of its salts) has been taken. In this connection the metal sorption is performed not for the creation of polymer metal composites and their following application, but for the study of possibilities of concentrating or removal of toxic metals from polluted waters of the environment, i. e. to apply the AF-polymers as sorbents. For example, it is known about the researches of chrome ions (Cr VI and Cr III ) sorption by the AF-polymer deposited on silica gel [4] or by microspheres of AF-polymer modified with simple alcohols. [5] In the first case, it has been defined that pH 3 is an optimal value for sorption of chrome ions and sorption capacity of AFP/silica gel makes up 65 mg/g at initial concentration of Cr VI of 200 mg·L À1 . [4] The second work has been shown that sorption of Cr VI and Cr I...