Electrolytic Efficiency

The rate of this charge transfer (coulomb/second) determines the detector response (ampere). In other words, maximum detector response is obtained at maximum charge transfer rate. A measure for the charge transfer rate is the electrolytic efficiency the fraction of analyte that is electrolyzed during passage through the cell expressed in percentage of total amount injected. 

Electrolytic efficiency (represented by analyte peak current) and noise as a function of the working electrode surface area is shown in Figure 3-7. 

Electrolytic efficiency should therefore be <20% for optimum signal-to-noise ratio amperometric detection... 

Thin-layer and wall-jet cells usually have typical electrolytic efficiencies in the optimum range. Porous working electrode cells however have typical electrolytic efficiencies of 100% with the inherent disadvantage mentioned above. 

Elemental iodine can be formed from aqueous iodide ion (by means of the oxidative electrode reaction, 21 b -I- 2e ) by passing a charge of 8.04 x 10 C. The amount of iodine was subsequently determined (by titration with aqueous thiosulfate) to be 0.239 mol. What is the electrolytic efficiency ... 

Worked Example 5.2. During the reductive formation of copper metal (from an aqueous solution of Cu " ), it is noticed that hydrogen gas is formed at the negative cathode, that is, in addition to the formation of a layer of fresh, pink copper metal. The volume of the gas at STP is 2.24 dm, and the overall electrochemical charge passed was 1.40 x 10 C. What is the electrolytic efficiency ... 

All the copper in a solution was removed by exhaustive electrolysis. The volume of the solution was 450 cm , and the stripping current was 3 x 10 C. What was the concentration of the copper Assume 100% electrolytic efficiency. 

Likewise, irradiation of an n-Si electrode in an aqueous electrolyte efficiently forms an insulating SiOx interface [3]. Reductive decomposition of semiconductors is rarely observed, although it has been claimed that certain p-type III-V semiconductors in the phosphide family decompose to form PH3. 

Hydrocarbon formation is more interesting in the electrochemical reduction of COj, since multielectron transfer is required in this process. In the electrochemical reduction of concentrated COj in the COj-methanol medium, the major products are still the two-electron transfer products, CO and methyl formate, at the Cu electrode, when tetrabutylammonium salts are used (Table 3). However, when tetraethylammonium salt was used as the supporting electrolyte, efficient formation of methane and ethylene was observed with good reproducibility. We defined the hydrocarbon selectivity as the ratio of the... 

The Alkaline Fuel Cell, AFC, is the most efficient low-temperature fuel cell presently available with a very high power density, therefore ideally appropriate for mobile applications. The AFC shows a similar performance as the PEFC, but with a much more demanding process control which is complicated because of the requirements of fuel purity (no CO2) and of the corrosive liquid electrolyte. Efficiencies of more than 60 % have been achieved with clean hydrogen and oxygen and noble electrode materials. The AFC was demonstrated to also work with a hydrogen-air system, in a 1 kW stack in Japan and in a 6 kW Russian system with more than 5(XX) h lifetime [34]. PEFC and AFC may play a... 

The lowest concentration able to cause coagulation of an electrolyte is called the coagulation threshold and its reciprocal is the electrolyte efficiency in precipitation (the higher the precipitation value, the less efficient the electrolyte is in the precipitation and vice versa). The value of the -potential at which coagulation occurs is the critical potential. 

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