Scholarly record
Bi-DOPED LEAD DIOXIDE NANOCATALYST FOR OXIDATIVE DECOMPOSITION OF ORGANICS
Abstract
The objectives of the present work are to develop technologies for the electrodeposition of mixed oxide nanocomposites with electrocatalytic activity towards the oxidative degradation of organic compounds. Oxidation of organics in the potential region of O2 evolution is supposed to proceed through the oxidation of water to hydroxyl radicals, which then may either be further oxidized to give molecular oxygen or interact with organic molecules in an oxygen-transfer reaction. Therefore, the ideal electrode material must ensure (i) the preferential adsorption of pollutants, (ii) the production of adsorbed hydroxyl radicals able to react with organics in a selective oxidation reaction (with as little as possible oxygen evolution) and (iii) a long term stability of performance. Oxides, mixed oxides and composite oxides are especially promising anode materials in view of their stability under oxidative conditions. PbO2 is one of the most investigated anode materials owing to its large electronic conductivity, chemical stability and low cost. Two basic pathways are envisaged for the optimisation of its properties: homogeneous doping and composite formation. In the present paper, the catalytic activity of PbO2 coatings deposited on Ti from acidic nitrate + fluoride baths containing Pb2+ and Bi3+ towards oxidative decomposition of toluene in sulphuric acid solution is investigated by voltammetric and electrochemical impedance spectroscopic measurements. The chemical composition of the obtained catalytic films is characterised by X-ray photoelectron spectroscopy and their structure and crystallite size by X-ray diffraction. The catalytic activity of the electrodes towards anodic oxidation of toluene in acidic medium is estimated both from current density vs. potential and polarisation resistance vs. potential plots. Measurements on similar electrodes have been carried out in sulphuric acid without toluene to eliminate the oxygen evolution reaction that proceeds in parallel to the oxidation of toluene. The kinetics of decomposition of toluene at different potentials is followed by UV spectrophotometry. A tentative mechanism of the process is proposed to account for the steady state and transient response of the nanocatalysts during oxidation of toluene.
Publication details
References11
S.Treimer, J.Feng, M.D. Scholten, D. C. Johnson, A.J. Davenport, J. Electrochem. Soc. 148 (2001) E459.
K.T. Kawagoe, D. C. Johnson, J. Electrochem. Soc. 141(1994) 3404.
K.L. Pamplin, D. C. Johnson, J. Electrochem. Soc. 143 (1996) 2119.
N.D. Popovic, J.A. Cox, D.C. Johnson, J. Electroanal. Chem. 455 (1998) 153.
N.D. Popovic, J.A. Cox, D.C. Johnson, J. Electroanal. Chem. 456 (1998) 203.
B. Velichenko, R. Amadelli, G. L. Zucchini, D. V. Girenko, F. I. Danilov, Electrochim. Acta, 45 (2000) 4341.
M.Musiani, P.Guerriero, Electrochim.Acta 44 (1998) 1499.
S.Catarin, I. Frateur, P.Guerriero, M.Musiani, Electrochim. Acta 45(2000)2279.
S.Catarin, P.Guerriero, M.Musiani, Electrochim.Acta 46 (2001) 4229.
M.Musiani, F.Furlanetto, R.Bertoncello, J.Electroanal. Chem. 465 (1999) 160.
R.Bertoncello, S.Catarin, I. Frateur, M.Musiani, J.Electroanal. Chem. 492 (2000)
View or Download full articleAccess options
SWS access login
Login as SWS Scientific CommitteeLogin as SWS Scientific PartnerLogin as SWS AuthorAuthors and approved SWS contributors will read and export their own linked papers after identity matching by SWS profile, email and SGEM GlobalID.
For librarian assistance: [email protected]
Purchase Instant Access
- Article can be downloaded after successful payment.
- Article may be used according to SWS library access terms.
- Article cannot be redistributed.