STUDIES ON THE ROLE OF OXIDATION-STATES OF THE PLATINUM SURFACE IN ELECTROCATALYTIC OXIDATION OF SMALL PRIMARY ALCOHOLS

The role of the oxidation state of a platinum polycrystalline surface in the electrocatalytic oxidation of C-1 to C-4 primary alcohols has b een studied by using electrochemical techniques, in situ FTIR spectros copy and X-ray photoelectron spectroscopy. The results revealed that t he oxidation state of the Pt surface plays a key role in the oxidation of primary alcohols, and demonstrated that the oxidation of C, to C, primary alcohols on a Pt electrode is controlled by the formation of s urface oxides on the Pt electrode at different potentials. It was foun d that the dependence of the reaction process on the oxidation states of the platinum surface yielded similar features in the cyclic voltamm ogram for oxidation of different primary alcohols at a Pt electrode. A ccording to the effects in the oxidation of primary alcohols, the surf ace oxides of platinum may be classified as active and poison species. The Pt surface oxides of higher oxidation states (Pt(OH)(3) and PtO2) formed at potentials above 1.0 V (SCE) were identified as poison sFec ies, while other lower oxidation states of Pt surface oxides such as P tOH, Pt(OH)(2) and PtO may be identified as the possible active specie s for primary alcohol oxidation. (C) 1997 Elsevier Science S.A.