Temperature electrolysis

Titanium Silicides. The titanium—silicon system includes Ti Si, Ti Si, TiSi, and TiSi (154). Physical properties are summarized in Table 18. Direct synthesis by heating the elements in vacuo or in a protective atmosphere is possible. In the latter case, it is convenient to use titanium hydride instead of titanium metal. Other preparative methods include high temperature electrolysis of molten salt baths containing titanium dioxide and alkalifluorosiUcate (155) reaction of TiCl, SiCl, and H2 at ca 1150°C, using appropriate reactant quantities for both TiSi and TiSi2 (156) and, for Ti Si, reaction between titanium dioxide and calcium siUcide at ca 1200°C, followed by dissolution of excess lime and calcium siUcate in acetic acid. 

W. Doenitz, and E. Erdle, High-temperature electrolysis of water vapor - Status of development and perspectives for application, International Journal Hydrogen Energy 10, 291-295(1985). 

High-Temperature Electrolysis of Steam 4.2.1 Reaction Scheme... 

Principle of high-temperature electrolysis of steam (reverse reaction of SOFC). 

Doenitz, W. and Eedle, E., High-temperature electrolysis of water vapor status of development and perspective for application, Int. ]. Hydrogen Energ., 10, 291,1985. 

Doenitz, W. et al., Recent advances in the development of high-temperature electrolysis technology in Germany, in Proc. 7th World Hydrogen Energy Conf., Moscow, 65,1988. 

Hino, R. et al., Present status of R D on hydrogen production by high temperature electrolysis of steam, Japan Atomic Energy Research Institute report, JAERI-Research 95-057,1995. 

Matsunaga, K. et al., Hydrogen production system with high temperature electrolysis for nuclear power plant, Paper 6282 in Proc. ICAPP 06, Reno, NV, June 4-8,2006. 

A typical example of the parallel synthesis based on the cation pool method is shown in Fig 4. A solution of a cation generated by low-temperature electrolysis is divided into several portions. To each portion, different nucleophiles are added to obtain products of different coupling combinations. 

In the cation flow method an organic cation is generated continuously by low temperature electrolysis using an electrochemical microflow reactor. The cation thus generated is immediately allowed to react with a carbon nucleophile in the flow system. This method, in principle, enables the manipulation of highly reactive organic cations. 

The a-phenylthioether 28 was oxidized in the absence of a nucleophile by low temperature electrolysis (Scheme 15). The corresponding alkoxycarbenium ion pool 26 was formed, which exhibited a single set of signals in H and l3C NMR spectroscopy. The chemical shifts were quite similar to those obtained by the oxidative C-Si bond dissociation described in the previous section. Subsequently, the cation pool was allowed to react with allyltrimethylsilane to obtain the allylated product 27. 

S.H. Jensen, M. Mogensen, Perspectives of high temperature electrolysis using SOEC. Paper presented at 19th World Energy Congress 2004, Sydney (AU),... 

Nuclear thermochemical and high temperature electrolysis High temperature corrosion-resistant materials Advanced catalysts and membrane materials Durable electrode and seal materials for high temperature electrolysis... 

Hong HS, Chae US, Choo ST, Lee KS (2006) Microstructure and electrical conductivity of Ni/YSZ and NiO/YSZ composites for high temperature electrolysis prepared by mechanical alloying. J Power Sources 149 84-89... 

Utgikar V, Thiesen T (2006) Life cycle assessment of high temperature electrolysis for hydrogen production via nuclear energy. Int J Hydrogen Energy 31 939-944... 

The US is developing "advanced electrolysis - low temperature electrolysis using alkaline and PEM technologies (electrochemical compression, improved efficiency, lower cost, integration of renewable resources), and "high temperature solid oxide electrolysis under a US 3.5 million program. 

Consumption of the graphite is quite acceptable inert anode materials for these conditions are hard to find, but in any event involvement of C in reaction 17.20 reduces the electricity requirement of the energy-intensive electrolysis by nearly half. Other, less commonly used processes that involve lower temperature electrolysis of molten AICI3 (mp 183 °C, performed in a closed vessel to prevent sublimation) have been developed. In these, the aluminum is formed as a solid (mp 660 °C), and the anodes are not consumed. Of course, one has to convert AI2O3 to A1C13 first, and this is usually done using graphite (coke) anyway ... 

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