IngentaConnect A Disordered Copper-Palladium Alloy Used as a Cathode Material

Authors: Poizot, Philippe; Laffont-Dantras, Lydia; Simonet, Jacques

Source: Platinum Metals Review, Volume 52, Number 2, April 2008 , pp. 84-95(12)

Abstract:

A novel method of forming a palladised copper (Cu/Pd) interface of well defined structure is described. The CuPd alloy is straightforwardly obtained by immersing a copper substrate in acidic solutions of palladium salts. Depending on the composition of the salt/acid solution, the copper surface is virtually instantly covered with a CuPd deposit. With nitric and sulfuric acid solutions and the corresponding Pd(II)-based salt, the deposit is composed of nanoparticles of disordered CuPd alloy dispersed at the copper interface. The alloy-modified surface was successfully used as an efficient promoter of bond cleavage reactions, especially those of carbon-iodide and carbon-bromide bonds in alkyl halides. The catalytic activity is specifically characterised by a very large shift in potential as between the use of a regular glassy carbon surface and the palladised copper interface. With alkyl halides (RBr and RI), the shift toward less cathodic potentials is so large that it enables the one-electron cleavage of C-I and C-Br bonds. This method should enable the heterogeneous generation of free alkyl radicals as transients in electrochemical reactions. These novel cathodic materials could also be of considerable interest for the disposal of halogenated waste.