Periodic Variation of Exchange Current Density of Hydrogen Electrode Reaction with Atomic Number and Reaction Mechanism

A survey of recent results shows that the activity is a periodic function of the atomic number for each long period. It is concluded that the bulk properties of electrode dominate its activity. Also, decreases linearly with heat of adsorption or increases linearly with work function for the transition metals, but remains unchanged for the metals following them (the ascending metals). These relations are qualitatively interpreted by the catalytic and the electrochemical mechanism for the transition and the ascending metals, respectively.