Graphite felt

Graphite felt Graphite fiber Graphite fibers... 

Eig. 4. Constmction of a sodium—sulfur battery. A, Negative terminal B, springs plus graphite felt C, sulfur D, carbon E, sodium reservoir E, positive terminal G, iasulator H, aluminum sealing gaskets 1, steel case J, film of sodium K, P-alumiaa tube L, carbon felt M, wick N, aluminum can (67). 

Fig. 7. Horse-liver alcohol dehydrogenase (HLADH) catalyzed alcohol oxidation at a graphite felt anode modified by poly(acrylic acid) (PAA) under coimmobilization of ferrocene derivatives (Fc), diaphorase (Dp), and HLADH [39]...

If both electrodes have to be made of materials, that are available only as foils or sheets or are not machinable, or for example, for materials, such as graphite felt, a cell design like the one in Fig. 9 is not realizable. Inlet and outlet systems have to be integrated in the electrolyte compartments. The parallel-plate and frame design of a laboratory flow-trough cell in Fig. 10 consists of easy-to-produce parts, using the fixing method for PTFE tubes in Fig. 4. 

As a result, a highly enantioselective oxidation of (22) was achieved by using a TEMPO-modified graphite felt electrode in the presence of (—)-sparteine, where the enantiopurity of the remaining (22) was >99% and the current efficiency for (23) was >90% (Scheme 8) [51]. However, this selectivity has been questioned [52]. 

A variety of phenol couplings have been described. Those reported before 1991 have been reviewed [66]. 2-Naphthol (27) was oxidized to l,l -binaphthol (28) in high current efficiency on a graphite felt electrode coated with a thin poly(acrylic acid) layer immobilizing 4-amino-2,2, 6,6-tetramethylpiperidinyl-l-oxy (4-amino-TEMPO) (Scheme 10) [67]. 

MeCN, NaCI04 TEMPO-modified graphite felt anode... 

For cases directly comparable to the cyclization originating from (27) above, the yields of the product were not as high. However, a related reaction used in the synthesis of an 11-substituted dibenzo[a,d]-cycloheptenimine derivative was very successful as shown in Scheme 11 (Eq. 2) [32]. In this reaction, a controlled potential electrolysis of (33) led to the formation of the tetracyclic (34) in an 85% isolated yield. The reaction was performed on a 1 g scale using an undivided cell, a graphite felt anode, a stainless steel cathode, a saturated calomel reference electrode, and a 1% NaBF4 in 70 30 THF/water electrolyte solution. The electrolysis was scaled up further with the use of a flow cell. In this experiment, 200 g of (33) were oxidized in order to afford a 75% isolated yield of (34). 

Redox" electrolysis-constant current (graphite felt electrodes)... 

Coupling A graphite felt electrode chemically modified with TEMPO led to the enantioselective electrocatalytic coupling of 2-naphthol, 2-methoxynaphth-alene and 10-hydroxyphenanthrene with high enantioselectivity (up to 98% ee) in the presence of (-)-sparteine as a chiral base [366]. 

In an enantiomer-differentiating oxidation at a poly-(L-valine)-coated Pb02 anode, rac-2,2-dimethyl-l -phenyl-1 -propanol was partially oxidized leaving 43% optically pure (5)-alcohol [371]. At a TEMPO-modified graphite felt anode rac-1-phenyl-ethanol has been enantioselectively oxidized in the presence of (-[-sparteine leaving 46% of the (/ [-alcohol with 99.6% ee [372]. However, under the same conditions, an exclusive dehydrogenation of (-[-sparteine to the iminium salt without oxidation of the alcohol was found [373]. 

Polymer-CONH MeCN-NaCl04/2,6-Lutidine-(C) C = graphite felt 90 112-115... 

A. Bauer, E. L. Gyenge, and C. W. Oloman. Direct methanol fuel cell with extended reaction zone anode PtRu and PtRuMo supported on graphite felt. Journal of Power Sources 167 (2007) 281-287. 

Graphite felt anode modihed by spiro-type chiral A-oxyl mediated enantioselective oxidation of primary alcohols proceeded with excellent efficiencies (equation 26)". ... 

Supported electrodes. The mixture of catalyst and charcoal is poured into the space between two mechanically rigid walls, with asbestos paper as support and a graphite felt or metal sheet as current collector. No binder is necessary. With such electrodes, both liquid and gaseous working materials can be studied. For the experiments with dissolved fuels described in Section 4.2, we used modified electrodes of this type 6 mg chelate was mixed with 6 mg soot and poured between two graphite felt discs. 

Tetrahydroisoquinoline-l-carboxylic acids have been anodically decarboxylated in MeOH-NaOMe on a graphite felt anode, giving 3,4-di-hydroisoquinolines (50-90%)417 This may be an example of a pseudo-Kolbe reaction in support of Hahn s theory of the biosynthesis of isoquinoline alkaloids by providing a laboratory analogy for the crucial decarboxylation step. 

Graphite felt as electrode material [ELECTROCHEMICAL PROCESSING - ORGANIC] (Vol 9)... 

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