Collect. Czech. Chem. Commun. 2001, 66, 67-80

Electrocatalysis of Hydrogen Evolution by Transition Metal Complexes

Michael Heyrovský

J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Prague 8, Czech Republic


Voltammetric reduction of monothiocyanate complexes of the iron group metals is accompanied by catalytic evolution of hydrogen in two potential regions. Around -1.3 V vs SCE, hydrogen is evolved at the surface of the electrodeposited metal, around -1.6 V at the surface of mercury. The catalyst is the protonated reduced, zero-valent form of the complex which has limited stability. Minor differences in behaviour of the complexes of the three metals are due to different values of their complexation constant.

Keywords: Transition metals; Thiocyanate complexes; Electroreduction; Mercury electrode; Hydrogen catalysis; Electrolysis; Voltammetry; Polarography; Cobalt; Iron.

References: 33 live references.