Revealing the concentration of hydrogen peroxide in fuel cell catalyst layers by an in-operando approach

• To evaluate the H2O2-tolerance of non-Pt oxygen reduction reaction (ORR) catalysts as well as investigate the H2O2-induced decay mechanism, the selection of an appropriate H2O2 concentration is a prerequisite. However, the concentration criterion is still unclear because of the lack of in-operando methods to determine the actual concentration of H2O2 in fuel cell catalyst layers. In this work, an electrochemical probe method was successfully established to in-operando monitor the H2O2 in non-Pt catalyst layers for the first time. The local concentration of H2O2 was revealed to reach 17 mmol/L, which is one order of magnitude higher than that under aqueous electrodes test conditions. Powered by the new knowledge, a concentration criterion of at least 17 mmol/L is suggested. This work fills in the large gap between aqueous electrode tests and the real fuel cell working conditions, and highlights the importance of in-operando monitoring methods.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

Fuel cells

Oxygen reduction reaction

Non-Pt catalyst layer

H 2 O 2 concentration

Catalyst degradation

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)