In situ FTIRS studies of kinetics of HCOOH oxidation on Pt(110) electrode modified with antimony adatoms

The electrochemical behavior of irreversibly adsorbed antimony on a Pt(110) electrode (Pt(110)/Sb) with various coverages was studied using cyclic vol tammetry. The kinetics of HCOOH oxidation via reactive intermediates on Pt( 110)/Sb were investigated quantitatively by employing the potential step te chnique and in situ FTIR spectroscopy. The results demonstrated that Sb ada toms were stable on Pt(110) when the electrode potential was below 0.45 V ( SCE). It has been revealed that the dissociative adsorption of formic acid can be inhibited by the presence of Sb-ad on the Pt(110) surface. The elect rocatalytic effects of Sb-ad towards HCOOH oxidation consist in a negative shift of the oxidation potential (about 350 mV) and the enhancement of the oxidation current. Based on the data processing method of integration trans form developed in our previous papers, the kinetics of HCOOH oxidation on P t(110)/Sb electrodes of different theta (Sb) have been investigated quantit atively, and both the rate constant k(f) and the transfer coefficient beta were determined and reported. (C) 2001 Elsevier Science B.V. All rights res erved.