Platinum Metals Rev., 1963, 7, (2), 65
Electro-organic Synthesis at Controlled Potentials
Mercury Cathode and Platinum Gauze Anode
Although catalytic hydrogenation and other chemical reduction processes are employed in the synthesis of many organic chemicals, their application is sometimes limited by lack of selectivity. An alternative method of reducing organic compounds—controlled potential electrolysis—has been investigated recently by W. H. Harwood, of Continental Oil Company, and R. M. Hurd and W. H. Jordan, of Tracor Inc., using nitrobenzene as the starting material (Ind. Eng. Chem., Process Design & Development, 1963, 2, (1), 72-77).
Electrolyses were carried out over the potential range—0.4 to—0.9 volt in sulphuric acid solutions, in a cell with a platinum gauze anode, a mercury pool cathode and a saturated calomel reference electrode. A high current capacity potentiostat, developed recently, maintained potential control. The various proportions of p -aminophenol, aniline, azoxybenzene and p -phenetidine produced were dependent on the electrolysis time and on the potential used.
The results of this laboratory-scale investigation indicate that potential control is effective in directing the course of electrochemical reduction reactions and in producing higher yields of some reduction products than are obtainable with chemical reducing agents. On an industrial scale, this technique may have many applications in the manufacture of organic compounds.