Degradation studies of PEMFC cathodes based on different types of carbon

• In this study different accelerated degradation tests were used evaluating three different carbon supports as well as a thin model electrode. Cyclic ADTs, by 1000 cycles beween 0.6 and 1.2 V in nitrogen, did not degrade the porous electrodes to any larger extent in terms of oxygen reduction activity, whereas a significant loss of electrochemical surface area was seen, often more than 50%. Potentiostatic hold at 1.4 V during 3 h, did not permanently degrade the electrodes but instead an improved activity was obtained after rest during night. A correlation of increase in double layer capacitance and improved performance was seen and believed to be caused by the good proton conductivity of carbon surface oxides. CO-stripping peaks revealed that the humidity and wetting of Nafion™ may have caused the observed temporary changes during the potentiostatic hold. ©The Electrochemical Society.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Keyword

Accelerated degradation tests

Carbon support

Carbon surface oxides

Degradation study

Double-layer capacitance

Electrochemical surface area

Oxygen Reduction

PEMFC cathode

Porous electrodes

Potentiostatics

Degradation

Electrolytic reduction

Membranes

Oxygen

Proton exchange membrane fuel cells (PEMFC)

Protons

Stripping (dyes)

Electrochemical electrodes

Publication and Content Type

ref (subject category)

kon (subject category)