Oxidative coupling electrolytic

The oxidative coupling of CH4 (OCM) in solid oxide fuel cells has attracted considerable attention in recent years because of the strong interest in the production of C2 hydrocarbons from natural gas. Work in this area utilizing solid electrolytes prior to 1999 has been reviewed.53... 

S. Seimanides, P. Tsiakaras, X.E. Verykios, and C.G. Vayenas, Oxidative Coupling of Methane over Yttria-doped Zirconia Solid Electrolyte, Appl. Catal. 68, 41-53 (1991). 

Scheme 17. Mechanism for Electrolyte Oxidation Coupled with Spinel Disproportionation and Mn + Dissolution...

At elevated temperatures, there are five possible reactions that can occur between the cell components (1) thermal decomposition of bulk electrolyte (2) chemical reduction of electrolyte by the anode (3) chemical oxidation of electrolyte by the cathode (4) thermal decomposition of the cathode and anode or (5) melting of the separator and the consequent internal short. To identify which of these contributes the decisive amount of heat that is critical in initiating the thermal runaway, it is necessary to study the thermal responses of these individual components or component couples separately. 

The formation of bicarbazoles can also be achieved electrolytically in acetonitrile solution once again, at the anode, the carbazole cation radical is produced and dimerizes. The further oxidation of 3,3 -bicar-bazole under these conditions with loss of two electrons and formation of a dication-diradical was demonstrated. Anodic oxidative coupling occurs at nitrogen best in the presence of collidine, presumably via deprotonation. 

C6H4CI2 and. Bl1 CIO as the electrolyte, only GeN(Bu )CH=CHNBu showed a single reversible oxidation couple, whereas the saturated analogue exhibited a reversible couple only at its second oxidation step. ""... 

Despite the fact that the respective reversible one-electron oxidation couples of (34), (37), and (38) proved insensitive to the presence of alkali metal cations, replacing the Et4NPF6-supporting electrolyte with NaPF6, KPF6, or LiC104 resulted in significant one-wave anodic shifts with compounds (35) and (36), of up to 110 mV with Na+ and (36). 

Refs. [i] Torii S, Tanaka H (1991) Carboxylic acids. In LundH, BaizerM (eds) Organic electrochemistry. Marcel Dekker, New York [ii] Schaefer HJ (1991) Electrolytic oxidative coupling. In Lund H, BaizerM (eds) Organic electrochemistry. Marcel Dekker New York... 

The purpose of the present chapter is to summarize the electrochemical oxidation of hydrocarbons with special reference to the electrode processes involved. The reader may also find material of interest in Chapters 22 (Electrolytic oxidative coupling), 24 (Anodic substitution and addition), and 32 (Conducting polymers). 

Electrolytic formation of carbon bonds during formation of heterocyclic compounds occurs in the reduction of ketones to pinacols, in the hydrodimerization reaction, in some radical coupling reactions, and in the oxidative coupling of activated aromatic systems. 

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