Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-V-20Al,Cu-PILLARED CLAYS AS CATALYST IN ENVIRONMENTALPROTECTIONZorica Mojović, Predrag Banković, Aleksandra Milutinović-Nikolić,Jasmina Dostanić, Nataša Jović-Jovičić, Dušan JovanovićInstitute of Chemistry Technology and Metallurgy, Department of Catalysis and ChemicalEngineering, Njegoševa 12, 11000 Belgrade, Republic of Serbia,Phone: +381-11-2630-213; Fax: 381-11-637-977; E-mail: snikolic@nanosys.ihtm.bg.ac.yuIntroductionToluene is pollutant classified into the group of extremely dangerous compounds to theenvironment. Since toluene is a common contaminant in waters in the vicinity of oil refineriesand the amount of toluene in drinking water should not exceed 1 ppm, preventing toluenefrom getting to water streams is an important task. The techniques usually adopted to achievewater purification from toluene are largely based on the use of phase separation methodsand/or adsorption on active suspended materials as well as biodegradation [1]. There areseveral drawbacks of these methods, including the inability of quantitative removal ofpollutants or the fact that they are time consuming and effective only at low concentrationlevels [2, 3]. Oxidation of toluene into nontoxic carbon dioxide and water might be theoptimal solution.In order to perform water purification from toluene Al-Cu pillared clay (PILC) wassynthesized and tested as catalyst in the oxidation of toluene in two different catalyticreactions at moderate temperatures: catalytic wet peroxide oxidation (CWPO) usingsynthesized Al-Cu PILC as catalyst and electrooxidation in acid solution using Al-Cu PILC aselectrode material.ExperimentalSmectite clay (≤2 µm) was pillared using procedure given by Kloidas et al. [4], whileCWPO of toluene was carried out at 310 K analogue to the procedure given for phenoldegradation [5]. The initial toluene and H 2 O 2 concentrations were 2 mM and 40 mM,respectively. Aliquots were taken at predetermined periods of time and, after filtrationanalyzed by gas chromatography.For the purpose of electrocatalytic reaction the synthesized Al PILC and Al-Cu PILCwere enriched with carbon black, suspended in Nafion solution and deposited on glassycarbon. The reference electrode was Ag/AgCl in 1M KCl, while a platinum foil served as acounter electrode. The electrocatalytic activity of the PILC based electrodes were analyzed in0.1 M H 2 SO 4 containing 1 – 5 mM toluene solution using cyclovoltammetry.494