Electrocatalytic effects in the electrochemical reduction of pyrazine on single crystal IB metal electrodes

Due to the presence of the second nitrogen atom, pyrazine has an increased affinity for electrons and lower energies of the empty orbitals than pyridi ne. For this reason the electrochemical reduction of pyrazine takes place a t considerably less negative potentials than that of pyridine. The reductio n of pyrazine on Cu(111), Ag(111) and Au(111) electrodes in neutral aqueous media has been found to take place in one step as previously reported for Hg. The potential region and the current densities associated with this pro cess were, however, observed to depend significantly on the electrode natur e. Pyrazine was also found to be involved in a chemical interaction with th e hydrogen atoms resulting in the water electro-reduction process occurring on Au(111) and Cu(111). The specific interaction of water with the single crystal electrodes turned out to be an important factor for developing the reduction of the organic molecule, both chemically and electrochemically. ( C) 2000 Elsevier Science S.A, All rights reserved.