Study of the Mechanism of the Hydrogen Evolution Reaction at Raney Nickel Electrodes in the Presence of Organic Compounds

1994 ◽  
Vol 141 (4) ◽  
pp. 975-982 ◽  
Author(s):  
Amoy Kam Cheong ◽  
Andrzej Lasia ◽  
Jean Lessard
Keyword(s):  
Hydrogen Evolution ◽  
Organic Compounds ◽  
Raney Nickel ◽  
Hydrogen Evolution Reaction ◽  
Nickel Electrodes

Influence of adsorption of organic compounds and surface heterogeneity on the hydrogen evolution reaction

1997 ◽  
Vol 75 (11) ◽  
pp. 1615-1623 ◽  
Author(s):  
Andrzej Lasia
Keyword(s):  
Kinetic Parameters ◽  
Hydrogen Evolution ◽  
Organic Compounds ◽  
Hydrogen Evolution Reaction ◽  
Surface Heterogeneity ◽  
Adsorbed Hydrogen ◽  
Heterogeneous Surfaces ◽  
Tafel Slopes ◽  
Adsorption Energies ◽  
Temkin Adsorption Isotherm

The hydrogen evolution reaction on rough or porous surfaces often leads to low Tafel slopes that cannot be explained in terms of the Volmer–Heyrovsky–Tafel mechanism. In addition, adsorption of organic compounds and ions causes an increase in the Tafel slopes. To explain such behavior, a concept of distribution of adsorption energies on heterogeneous surfaces, leading to a distributed kinetics, was studied. Simulations of the dependence of the current and the surface coverage by adsorbed hydrogen on overpotential are presented for different values of the kinetic parameters in the absence and presence of the adsorbed foreign substances. These results were compared with those obtained using the Frumkin/Temkin adsorption isotherm. It was found that for some kinetic parameters and a flat distribution of adsorption energies, low Tafel slopes, similar to those observed experimentally, are obtained. Keywords: hydrogen evolution, adsorption, heterogeneous surfaces, distributed kinetics, Frumkin/Temkin isotherm.

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