Supporting information for:
Optimization of PEM Fuel Cell Membrane Electrode Assemblies
for Transition Metal Ion-Chelating Ordered Mesoporous Carbon
Cathode Catalysts
Johanna K. Dombrovskis1*, Cathrin Prestel1, Anders E.C. Palmqvist1
1
Chalmers University of Technology, Department of Chemical and Biological Engineering, Applied Surface
Chemistry, SE-412 96 Göteborg, Sweden
[*] Corresponding author, harterj@chalmers.se
1. Experimental methods
Specific surface area, pore volume and pore size distribution of degassed catalyst powders were measured by
nitrogen adsorption and desorption using a TriStar 3000 instrument from Micromeritics. All samples were
degassed in a vacuum oven for 4 hours at 225 °C. The surface area was calculated using the BET algorithm [S1]
while pore volume and pore size distributions were deduced from the BJH algorithm [S2,S3].
Small angle X-ray scattering (SAXS) experiments were done using a Hecus System 3 instrument with a
Cu Kα X-ray source.
2. Supplementary figures and tables
Figure X1. Nitrogen physisorption curves (a) and SAXS patterns (b) of an as-synthesized Fe/N-OMC sample
polymerized at 1100 °C (black - line) and the same sample after grinding (blue - dash).
Table X1: Surface area (SBET), pore volume (Vp), average pore diameter (Ø) and t-plot micropore area of an assynthesized Fe/N-OMC sample polymerized at 1100 °C and the same sample after grinding.
Catalyst
as synthesized
after grinding
SBET / m2g-1
Vp / cm3g-1
Øads / nm
636
698
0.604
0.652
4.18
4.27
t-plotmicropores /
m2g-1
110
121
Figure X2. Nyquist plot of the electrochemical impedance spectroscopy (EIS) measurements at room
temperature and 0.6 V vs. ERHE using an optimized cathode when freshly prepared (black – filled square) and
after 8 h of use (black – empty square) as well as a cathode prepared from an extensively mixed Nafion catalyst
ink when freshly prepared (red – filled square) and after 8 h of use (red – empty square).
3. Supplementary references
[S1]
[S2]
[S3]
Brunauer, S.; Emmett, P.H.; Teller, E. J. Am. Chem. Soc. 1938, 60, 309-319.
Barrett, E.P.; Joyner, L.G.; Halenda, P.P. J. Am. Chem. Soc.1951, 73, 373-380.
Joyner, L.G.; Barrett, E.P.; Skold, R. J.Am. Chem. Soc. 1951, 73, 3155-3158.