Veronique Reid

Electrochemical behaviour of DSA type electrodes prepared by induction heating

DSA type electrodes (IrOx/Ti) were prepd. by induction heating technique which allows a rapid decompn. of the precursor under anaerobic conditions. With this type of electrode, an activation process is obsd. in cyclic voltammetry which can be related to the presence of metallic Ir within the coatings. The electrooxidn. of alcs. in acid medium was studied by cyclic voltammetry. In the presence of alcs., a large current enhancement was obsd. at E >= 1.3 V/normal H electrode. This great reactivity can be due to high iridium oxidn. states, Ir(V) and Ir(VI), present in the oxide layer in this potential range. [on SciFinder (R)]

Characterization of DSA type electrodes prepared by rapid thermal decomposition of the metal precursor

A new technique is presented for the prepn. of DSA type electrodes. In this technique, the precursor is rapidly decompd. on the substrate by treatment in an induction electromagnetic field. The effects of the rapid heating of H2IrCl6.6H2O precursor on Ti substrate on the morphol. and the compn. of the coating are presented. Formation of metallic Ir is obsd. using this technique. [on SciFinder (R)]

Pt/Ti electrode preparation methods: application to the electrooxidation of isopropanol

Platinum coatings on Ti were prepared by a two-step process: partial thermal decomposition of chloroplatinic acid followed by electroreduction of the coating. Effects of preparation temperature and of cathodic polarization on the roughness factor were studied. Roughness factors greater than 570 were achieved, leading to an enhancement of the activity towards isopropanol electrooxidation in 1 M H2SO4.

Coplanar interdigitated band electrodes for electrosynthesis. Part 6. hypochlorite electrogeneration from sea water electrolysis

A novel design for interdigitated band electrodes is described. The electrode is built by successive printing of conductive and insulating layers on a steel substrate. This geometry exhibits a high performance for the hypochlorite electrogeneration from seawater. The active chlorine concn. reached at the end of the electrolysis varies from 0.5 to 10 g L-1, depending on the no. of electrodes, their configuration in batch or single flow mode, the flow rate and the c.d. This geometry also limits scale development at the cathode. [on SciFinder (R)]

Single Flow Electrochemical Microreactor Application to Furan Methoxylation

Interdigitated band electrodes are fabricated using screen printing technology and laser ablation methods in order to pattern electrodes featuring inter-electrode gaps down to 30 µm. The electrochemical microcell is tested with a scheme reaction: the furan methoxylation. Various parameters are investigated including cell voltage, supporting electrolyte composition and bromide concentration. The results are presented in terms of conversion and current efficiencies as well as energy consumption. For instance, cells with inter-electrode gap of 100 µm allow 70% conversion with a current efficiency of 80% and an energy consumption of 1.5 kWh kg−1, for inlet methanol solutions containing 50 mM of furan and 5 mM of bromide salt at a flow rate of 85 µl min−1. It is worth noticing that the improvement brought about by this configuration relates to energy as well as selectivity. When compared to others electrochemical cells (bipolar packed bed cells or pump cells) in batch configuration, the microreactors feature 50% decrease of the energy consumption and considerable improvement in selectivity as only one by-product is detected in the outlet solution compared to the numerous by products usually obtained. Moreover, the reduced amount of salt, the high selectivity and the quasi-total conversion of the furan reduce the successive purification processes of the outlet solution.