Activity and long-term stability of PEDOT as Pt catalyst support for the DMFC anode

Abstract

The feasibility of using poly(3,4-ethylenedioxythiophene) (PEDOT) as Pt catalyst support for direct methanol fuel cell (DMFC) anodes was investigated. Measurements with freshly prepared Pt-PEDOT/C electrodes showed poor activity for methanol oxidation in a half-cell and a DMFC. A substantial enhancement in that activity was evident after either electrochemical over-oxidation of PEDOT or long-time storage of the Pt-PEDOT/C gas diffusion electrode (GDE) in air. Both procedures led to a reorganization and increase in porosity of the reaction layer, which obviously contributed to better methanol accessibility to Pt catalyst active centres. The effects of electrochemical activation and long-time storage in air on the morphology and elementary composition of the Pt-PEDOT layer were investigated by means of Hg porosimetry and SEM/EDAX. It was found that the increase in porosity was due to degradation of PEDOT characterized by a significant depletion of sulphur and oxygen in the conducting polymer matrix.

The Electrochemical Degradation of Poly(3,4-ethylenedioxythiophene) Films Electrodeposited from Aqueous Solutions

“…Electronic and electrochemical devices based on organic materials are light emitting diodes, sensors, actuators, organic thin film transistors, solar cells, memory devices, ion-selective electrodes, microelectrode arrays, fuel cells, etc. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Obviously, in all these applications the long term stability of the polymer is of particular concern.…”

Structural changes during the overoxidation of electrochemically deposited poly(3,4-ethylenedioxythiophene) films

“…light emitting diodes, sensors, actuators, organic thin film transistors, solar cells, memory devices, ion-selective electrodes, microelectrode arrays, fuel cells, etc. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Obviously, in all these applications the long term stability of the polymer is of particular concern.…”

Morphological changes in electrochemically deposited poly(3,4-ethylenedioxythiophene) films during overoxidation

“…Electronic and electrochemical devices based on organic materials are, e.g., light-emitting diodes, organic thin-film transistors, solar cells, memory devices, ion-selective electrodes, microelectrode arrays, fuel cells, etc. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Beyond doubt, the monitoring of the degradation of the polymer layers is of great importance for the long-term use of these devices.…”