Acta Phys. -Chim. Sin. ›› 2000, Vol. 16 ›› Issue (10): 906-911.doi: 10.3866/PKU.WHXB20001008

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An EQCM Investigation of the Mechanism of Surface Electro-oxidation of Formic Acid on Pt-electrode

Xiang Juan, Wu Bing-Liang, Chen Sheng-Li   

  1. Department of Chemistry,Wuhan University,Wuhan 430072
  • Received:2000-03-14 Revised:2000-05-07 Published:2000-10-15
  • Contact: Wu Bing-Liang E-mail:blwu@whu.edu.cn

Abstract:

The adsorption and oxidation of formic acid in a sulfuric acid medium on a platinum electrode were investigated using the time-resolved electrochemical quartz crystal microbalance(Time-resolved EQCM). A programmed potential step procedure was used to overcome the self- poisoning involved in the oxidation of formic acid. The results demonstrated that the reactive oxidation of formic acid produced COOHad as the first electron transfer process at the initial stage. It was a fast process corresponding to an oxidation current peak on the chronoamperometric plot. At the second stage, further oxidation of COOHad corresponded to a steady current and unchanged mass, which was a slow process. Based on the steady current of the further oxidation of COOHad at different adsorption potentials, the reaction rate constants and the transfer coefficient were obtained.

Key words: Formic acid, Pt electrode, Time-resolved EQCM, Adsorption, Rate constant