More than 95% of world chlorine production (~ 46.7 million metric tonnes, in 1999) is achieved using the chlor-alkaly process. Since 1970, activated (noble-metal-oxide-coated) titanium anodes have replaced the graphite anodes used in the diaphragm and mercury cell processes, allowing significant productivity improvements. Considering the above industrial impact, the chlorine evolution reaction (CLER) has been thoroughly investigated, also at different anode materials, with the aim of elucidating the reaction mechanism and characterizing the electrode material itself. Recently, important results have been achieved in the preparation of conductive diamond (e.g., highly boron-doped diamond (BDD) films) exhibiting an exceptional stability, both towards chemical and electrochemical oxidation. Among the different applications of this new material, its use as an anode for the CLER has been investigated in details. Besides, it has been tested as a support for noble-metal oxide films, showing to be particularly suitable for the study of the catalytic properties of noble-metal oxide modifications, avoiding the serious interference of the reactivity of the generally adopted metal supports. In the frame of this comprehensive research, the study has been extended to the kinetics of the bromine electrode at both the polycrystalline Pt and BDD electrodes, whose results will be discussed too.
Some aspects of the chlorine and bromine electrochemistry at different electrode materials
FERRO, Sergio
2004
Abstract
More than 95% of world chlorine production (~ 46.7 million metric tonnes, in 1999) is achieved using the chlor-alkaly process. Since 1970, activated (noble-metal-oxide-coated) titanium anodes have replaced the graphite anodes used in the diaphragm and mercury cell processes, allowing significant productivity improvements. Considering the above industrial impact, the chlorine evolution reaction (CLER) has been thoroughly investigated, also at different anode materials, with the aim of elucidating the reaction mechanism and characterizing the electrode material itself. Recently, important results have been achieved in the preparation of conductive diamond (e.g., highly boron-doped diamond (BDD) films) exhibiting an exceptional stability, both towards chemical and electrochemical oxidation. Among the different applications of this new material, its use as an anode for the CLER has been investigated in details. Besides, it has been tested as a support for noble-metal oxide films, showing to be particularly suitable for the study of the catalytic properties of noble-metal oxide modifications, avoiding the serious interference of the reactivity of the generally adopted metal supports. In the frame of this comprehensive research, the study has been extended to the kinetics of the bromine electrode at both the polycrystalline Pt and BDD electrodes, whose results will be discussed too.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
