TY - JOUR
T1 - Degradation study by start-up/shut-down cycling of superhydrophobic electrosprayed catalyst layers using a localized reference electrode technique
AU - Ferreira-Aparicio, Paloma
AU - Chaparro, Antonio M.
AU - Folgado, M. Antonia
AU - Conde, Julio J.
AU - Brightman, Edward
AU - Hinds, Gareth
PY - 2017/3/29
Y1 - 2017/3/29
N2 - Degradation of a polymer electrolyte membrane fuel cell (PEMFC) with electrosprayed cathode catalyst layers is investigated during cyclic start-up and shut-down events. The study is carried out within a single cell incorporating an array of reference electrodes that enables measurement of cell current as a function of local cathode potential (localized polarization curves). Accelerated degradation of the cell by start-up/shut-down cycling gives rise to inhomogeneous performance loss, which is more severe close to the gas outlet and occurs predominantly during start-up. The degradation consists primarily of loss of cathode catalyst activity and increase in cell internal resistance, which is attributed to carbon corrosion and Pt aggregation in both anode and cathode. Cells with an electrosprayed cathode catalyst layer show lower degradation rates during the first 100 cycles, compared with those of a conventional gas diffusion electrode. This difference in behavior is attributed to the high hydrophobicity of the electrosprayed catalyst layer microstructure, which retards the kinetics of corrosion of the carbon support. In the long term, however, the degradation rate is dominated by the Pt/C ratio in the cathode catalyst layer.
AB - Degradation of a polymer electrolyte membrane fuel cell (PEMFC) with electrosprayed cathode catalyst layers is investigated during cyclic start-up and shut-down events. The study is carried out within a single cell incorporating an array of reference electrodes that enables measurement of cell current as a function of local cathode potential (localized polarization curves). Accelerated degradation of the cell by start-up/shut-down cycling gives rise to inhomogeneous performance loss, which is more severe close to the gas outlet and occurs predominantly during start-up. The degradation consists primarily of loss of cathode catalyst activity and increase in cell internal resistance, which is attributed to carbon corrosion and Pt aggregation in both anode and cathode. Cells with an electrosprayed cathode catalyst layer show lower degradation rates during the first 100 cycles, compared with those of a conventional gas diffusion electrode. This difference in behavior is attributed to the high hydrophobicity of the electrosprayed catalyst layer microstructure, which retards the kinetics of corrosion of the carbon support. In the long term, however, the degradation rate is dominated by the Pt/C ratio in the cathode catalyst layer.
KW - cathode localized potential
KW - electrosprayed films
KW - Pt/C ratio
KW - reference electrode array
KW - start-up/shut-down degradation
KW - superhydrophobic catalyst layer
UR - http://www.scopus.com/inward/record.url?scp=85016547232&partnerID=8YFLogxK
U2 - 10.1021/acsami.6b15581
DO - 10.1021/acsami.6b15581
M3 - Article
AN - SCOPUS:85016547232
SN - 1944-8244
VL - 9
SP - 10626
EP - 10636
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 12
ER -