Analytical Applications for PEMFC
Polymer electrolyte membrane fuel cells (PEMFCs) are devices constructed by a large number ofmaterials, such as electrolyte membranes, catalysts and gas diffusion layers (GDLs). By applying
various analyses for the purpose such as the new material search or the material estimation withthe degradation test, it is possible to clarify "phenomenon" and "degradation part".
１．Material search
Estimation purposes
Validation of
preparing MEA
Design of
catalyst layer

Evaluation items

Analytical methods

Layer thickness, uniformity

SEM, EPMA, SEM-EDX

Dispersion state of catalyst

TEM, TEM-tomography

Dispersion of ionomer and void

AFM-IR, TEM, TEM-EDX

Quantitative analysis of void

Mercury intrusion method

Dispersion of ionomer in catalyst ink

AFM, GPC, NMR

Retrieval ofelectrolyte membrane

Cluster size analysis

DSC, XRD, TEM

Porosity, wettability,
water-shedding
quality

Volume of void

Evaluation of catalyst

Chemical structure analysis

Mercury intrusion method,
SEM (slice & view)

Wettability, permeability of water
Crystallite diameter, alloying degree

XRD

Distribution of core-shell catalyst

TEM, TEM-EDX

Chemical state of carbon support

Red ： Ionomer
Gray ： Carbon
Yellow : Pt particle

NMR, solid-state NMR

Contact angle,
Perm-porometry

Chemical state of catalyst■3D reconstruction image ofcatalyst layer by TEM-tomography

XAFS, XPS
Raman, XPS, XAFS

Quantitative analyses
・Ionomer coverages
Carbon surface area = 95336 (nm2)
Ionomer area in contact with carbon= 36604 (nm2)
Ionomer coverage to carbon = 38 (%)
・Ionomer thickness
Average thickness = 10.2 (nm)

■H2O2 exposure test

２．Durability test and stability test
Methods

Examination contentsH2O2 exposure test

Temperature：30 ~ 100℃
Humidity：10 ~ 95％RH

Mechanical test ofelectrolyte membrane

Tensile strength, coefficient ofexpansion, compression test

Temperature：30 ~ 80℃
Humidity：30 ~ 95％RH

Dissolution test

Identification of eluted material(Bipolar plate, GDL)

Dissolution test, ICP-MS

Trap

H2OSample

H2O2（membrane, catalytic layer etc.）*S. Honmura, et. al., Polymer Preprints, Japan vol. 54,
No.2 (2005).

After exposure test, to various analyzes
Degradation phenomena

Analytical methods

Deposition of catalyst in electrolyte membrane

SEM, EPMA, TEM

Structural change

Raman, IR, NMR

Condition and mobility of water in membrane
Qualitative & quantitative analysis ofdecomposition products
Change in molecular weight
Change of particle size in catalyst

Catalyst
layer

Chamber

WET

Air or N2

Dissolution and degradation of catalyst
Corrosion of carbon support
Impurity effect■S K-edge XANES spectra of catalyst
layer before/after sulfur poisoning
6Blank operation
Poisoning operation
Recovery operation

NMR, DSC
NMR, LC/MS/MS, IR, IC
GPC
TEM, XRD
TEM, XRD, XAFS, ICP
Raman, IR. XPS
ICP-MS, XPS, XAFS

Absorption(a.u.)

Ionomer

WET(for humidification)

３．Degradation

Electrolyte
membrane

30～100℃，10～95％RH（任意に設定可能）

DRY

・Test of chemical stability ofelectrolyte
・Elucidation of degradation
mechanism

Materials

20～100ml/min

Conditions

42

Judgment of
the sulfide

02460

2470

2480

2490

Energy(eV)

2500

2510

P01562表面科学第２研究室20161120-2
STC：開(20170405