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Methodologies and Advanced Characterizations of Photoelectrochemical Processes
Published in Anirban Das, Gyandshwar Kumar Rao, Kasinath Ojha, Photoelectrochemical Generation of Fuels, 2023
Camilla Tossi, Ornella Laouadi, Ilkka Tittonen, Aadesh P. Singh
Voltammetry was invented by the Czech chemist Jaroslav Heyrovský in 1922, for which he received the Nobel Prize in 1959. It was called polarography at the time, and it used a dropping mercury electrode (DME) as a WE, made of a glass capillary with an inner diameter of 0.1–0.05 mm connected via a rubber or plastic tubing to a mercury reservoir. This new technique allowed Heyrovský to measure the surface tension of mercury, which gave him information about the nature of the liquid-metal interface [29]. His first experiment consisted of immersing the DME and an RE into the solution under investigation and letting droplets of mercury regularly fall from the capillary into the studied solution. The weight of the droplets was plotted as a function of potential, giving the i-E curve [30], but it was done manually and tediously. In 1925 Heyrovský and Shikata developed an instrument that automatically acquired photographs of the i-E curves, the so-called Polarograph [31]. The choice of DME as an electrode brings a lot of advantages: mercury has a smooth surface and a high hydrogen overpotential, meaning that a large negative potential range can be obtained in an aqueous solution. Also, mercury displays a highly reproducible behavior and almost no contamination due to the continuously renewable surface while dropping [32].
Electrochemical Studies in Microemulsions
Published in Promod Kumar, K. L. Mittal, Handbook of Microemulsion Science and Technology, 2018
The electrochemical experiments are typically conducted in a three-electrode cell with working, counter, and reference electrodes. The current flows between the working and counter electrodes. The potential of the working electrode is recorded with respect to the reference electrode. Typical reference electrodes used in studying surfactant systems include the saturated calomel electrode (SCE) and the Ag/AgCl (saturated KCl) electrode. Carbon (glassy or pyrolytic), platinum, and mercury are generally used as the working electrode. A dropping mercury electrode (DME) or a static mercury drop electrode is common for polarography. Both solid electrodes and hanging mercury drop electrodes are used in voltammetry. The geometric surface area of the electrode varies from 1 to 10 mm2.
Techno-economic assessment of hydrogen production via dimethylether steam reforming and methanol steam reforming
Published in Indian Chemical Engineer, 2023
Shardul S. Rahatade, Nilesh A. Mali
However, DME has the potential of becoming a raw material for steam reforming because it is a potential clean fuel, it does not contain any harmful compounds and burns without producing any harmful pollutants such as NOx, SOx, particulate matter, and smoke. DME has similar properties to that of LPG and can be handled and stored in the same way as LPG [3]. The DME possesses a lot of advantages such as the high H/C ratio, high energy density, no toxicity, and no C–C bonds present. The absence of no C–C bonds leads to lesser carbon deposition on the catalyst surface [4].