Mechanism for elemental carbon formation in molecular ionic liquids

The electrochemical reduction of liquid ternary system lithium-sodium-potas sium carbonates were performed at 450 degrees C in order to obtain carbon d eposits on copper, nickel and glassy carbon electrodes. X-ray analysis show s that the deposit was made of amorphous carbon. Moreover, it contains lith ium carbide and several lithium oxides which were identified by their X-ray diffraction patterns. The influence of the electrode potential on the natu re of the deposited material was studied. The amount of lithium compounds i ncreased as the potential became more cathodic. Fine carbon powder was obta ined with a specific area (B.E.T.) of 650 m(2) g(-1). Further data are repo rted to contribute to the mechanism of carbon generation including identifi cation of intermediate reaction steps such as the formation of subcarbonate CO2Li2 which is assumed to be a lithium oxide adsorbed at the surface of t he carbon deposit, (C) 1994 Elsevier Science B.V. All rights reserved.