Electrocatalysis on Electrodes Modified by Underpotential Deposition

Electrodes modified by underpotential deposition of metal were subjected as electrocatalysts to reduction of oxygen,oxidation of formic acid, and other processes in which polycrystalline metal substrates were used (see review in Ref. 151). Electrocatalysis of single-crystal electrodes modified by underpotential deposition was also investigated, as reviewed by Ad2iC.  

Since a well-defined condition of the underpotential deposition metal at a definite coverage is better for studying its modified surface at a definite coverage, an irreversibly adsorbed underpotential deposition metal is desirable Sb on Pt(lll) for CO oxidation,Bi and Te on Pt(lOO) for formic acid oxidation, Sb + Bi on Pt(lOO) for formic acid oxidation, and others found in these references. 

In most of the works referred to in this section, catalytic activities were observed through cyclic voltammograms, which exhibit only primary trends for electrocatalysts. The observation of steady current at certain potentials is quite important because the degree of catalytic activity under the steady-state condition must be known in order to develop 

---