STUDY OF THE ELECTROCATALYTIC INFLUENCE OF PT RU AND RU ON THE OXIDATION OF RESIDUES OF SMALL ORGANIC-MOLECULES/

Differential electrochemical mass spectrometry was employed for the in vestigation of the electrocatalytic activity of Ru deposits and of bim etallic Pt/Ru co-deposits. Using these modified electrodes the oxidati on of the residues of CO, HCOOH and CH3OH was studied by cyclic voltam metry. The corresponding mass intensity of CO2 (m/z = 44) during the a dsorbate oxidation clearly shows an increasing mass signal for CO2 mor e than 200 mV more negative at Pt/Ru in comparison with that on pure P t. In addition, the formation of methanol residues on the Pt/Ru surfac es was studied and compared with those on pure Pt and pure Ru. It is s hown that the peak potentials for the formation of CH3OH residues at P t/Ru surfaces are shifted by 70 mV in the negative direction compared with pure Pt, while pure Ru shows no formation of methanol residues. N evertheless, on the Ru surfaces CO and HCOOH do form adsorbates. The r esults presented demonstrate that the bifunctional mechanism, proposed earlier for the methanol oxidation at Pt/Ru, must be modified.