THE HYDROGEN PRESSURE EQUIVALENT TO THE OVERPOTENTIAL - OBSERVATION ON PD HYDROGEN ELECTRODE AND INTERPRETATION ON THE BASIS OF A MIXED-CONTROLLED MECHANISM
M. Enyo, THE HYDROGEN PRESSURE EQUIVALENT TO THE OVERPOTENTIAL - OBSERVATION ON PD HYDROGEN ELECTRODE AND INTERPRETATION ON THE BASIS OF A MIXED-CONTROLLED MECHANISM, Electrochimica acta, 39(11-12), 1994, pp. 1715-1721
A quantitative analysis is presented of the hydrogen pressure that is
in equilibrium with adsorbed hydrogen at a Pd cathode and discussed on
the basis of a mixed-controlled Volmer-Tafel mechanism of the hydroge
n electrode reaction. Experimental evidence which supports this, but n
ot the Volmer-Heyrovsky mechanism on a smooth Pd electrode, are discus
sed. The effective pressure can be evaluated from the slowly decaying
overpotential component appearing in overpotential decay transients. E
vidence is given which indicates that the overpotential component is i
ndeed caused by adsorbed hydrogen on the electrode surface. The effect
s of some catalytic poisons, which augment the equivalent pressure und
er otherwise the same conditions, are investigated.