Dimensionally stable anodes DSA

The most common oxidation states and the corresponding electronic configuration of mthenium are +2 and +3 (t5 ). Compounds are usually octahedral. Compounds in oxidations states from —2 and 0 (t5 ) to +8 have various coordination geometries. Important appHcations of mthenium compounds include oxidation of organic compounds and use in dimensionally stable anodes (DSA). 

Miscellaneous. Iridium dioxide, like RUO2, is useful as an electrode material for dimensionally stable anodes (DSA) (189). SoHd-state pH sensors employing Ir02 electrode material are considered promising for measuring pH of geochemical fluids in nuclear waste repository sites (190). Thin films (qv) ofIr02 ate stable electrochromic materials (191). 

Anode Applications. Graphite has been used as the primary material for electrolysis of brine (aqueous) and fused-salt electrolytes, both as anode and cathode. Technological advances, however, have resulted in a dimensionally stable anode (DSA) consisting of precious metal oxides deposited on a titanium substrate that has replaced graphite as the primary anode (38—41) (see Alkali and chlorine products). 

Appreciable interest was stirred by the sucessful use of nonmetallic catalysts such as oxides and organic metal complexes in electrochemical reactions. From 1968 on, work on the development of electrocatalysts on the basis of the mixed oxides of titanium and ruthenium led to the fabrication of active, low-wear electrodes for anodic chlorine evolution which under the designation dimensionally stable anodes (DSA) became a workhorse of the chlorine industry. 

Ru02 is an important electrode material for industrial anodic processes. Special attention is deserved by the so-called dimensionally stable anodes (DSA) invented by H. B. Beer in 1968. These are formed by a layer of a microcrystalline mixture of Ti02 and Ru02 (crystallite size less thn 0.1 jum) on a titanium support (Fig. 5.26). This material is suitable as anode for chlorine and oxygen evolution at high current densities. For industrial chlorine production, it replaced the previously used graphite anodes. These... 

Ru02-based coatings on Ti show excellent properties as dimensionally stable anodes (DSA). 

The dimensionally stable anodes (DSA ) consist of a titanium base metal covered by a thin conducting layer of metal oxide or mixed metal-oxide oxides. Since their discovery by Beer (1966) in the late 1960s, a lot of work has been done on DSA and on finding and preparing new coating layers for many electrochemical... 

Dimensionally stable anode (DSA) - dimensionally stable electrodes, - electrode materials, subentry - ORTA... 

Dimensionally stable anodes (DSAs) are used in all the three cell technologies to conserve energy, reduce impurities, and lengthen cell life.28,29 Prior to this development, the cell anodes were made of graphite. The new anodes have a titanium substrate, which has... 

The technologically important dimensionally stable anodes (DSA) are thermally prepared mixed oxide films supported on an inert substrate, usually Ti, which contain Ru02 as the catalytically active component. These anodes exhibit high performance in the industrial generation of chlorine. 

Kalu and Oloman [75] studied the simultaneous synthesis of alkaline hydrogen peroxide and sodium chlorate in a bench-scale flow-by single-cell electrochemical reactor. A schematic of the electrode conditions is shown in Fig. 18. Graphite felt was used as the cathode to synthesize peroxide from 0.5 -2.0 M NaOH chlorate was the product at a dimensionally stable anode (DSA). The anodic and cathodic reactions were as follows ... 

Ruthenium dioxide-based materials represent the catalyst for the industrial anodic production of chlorine. There is no doubt that, in the case of dimensionally stable anodes (DSA ), the technological innovation was adopted by industry [21] a few... 

As shown by the volcano plots of Figs 25 and 39 [139], Pt and Pt-Ru alloys are among the most active electrocatalysts for the oxygen evolution reaction. However, Ru02, which is also the main component of dimensionally stable anode (DSA) electrodes, is significantly more active (Fig. 25). 

Using carbon or, better, a titanium surface activated with a mixture of titanium and ruthenium oxides as an anode material (the latter is the so-called dimensionally stable anode (DSA) [7, 12]), chlorine ions are discharged... 

Dimensionally stable anodes (DSAs) made of a corrosion-resistant titanium screening have been adopted by both mercury cell and diaphragm cell operators. A baked-on rutile titanium dioxide paste used with these electrodes decreases the electrochemical overvoltage and raises practical operating current densities. While significantly more expensive than graphite, this anode... 

The introduction of the dimensionally stable anode (DSA) has had a major impact on the production of chlorine and caustic by the... 

Different techniques have been used for the preparation of the so called Dimensionally Stable Anodes (DSA) which consist of a thin layer of active coating (1 - lOp) on an inert substrate usually titanium. 

Most metals are stable in operation as cathodes but unstable as anodes. Satisfactory stability is at least 1,000 hours of continuous operation and preferably 10,000 hours for commercial operations. Of the many categories of electrodes developed, four merit special attention for use in electrosynthesis in different media chemically modified electrodes (CMEs), dimensionally stable anodes (DSAs), conducting polymers, and catalytic cathodes (especially of Raney nickel). 

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