TY - JOUR
T1 - Immunity of the Fe-N-C catalysts to electrolyte adsorption: phosphate but not perchloric anions
AU - Hu, Yang
AU - Jensen, Jens Oluf
AU - Pan, Chao
AU - Cleemann, Lars Nilausen
AU - Shypunov, Illia
AU - Li, Qingfeng
PY - 2018
Y1 - 2018
N2 - Non-precious metal catalysts (NPMCs), particularly the type based on carbon-supported FeNx
functionalities (Fe-N-C) are a very promising material for replacing
the rare and costly platinum-based catalysts in polymer electrolyte
membrane fuel cells (PEMFCs). Evaluation of these materials is most
often carried out, like for Pt-based catalysts, in dilute perchloric
acid by assuming its non-adsorbing nature on the active sites. The
assumption is however not true. In this work, a typical Fe-N-C catalyst
was first synthesized by high-pressure pyrolysis in the presence of
carbon support and thoroughly characterized in terms of morphology,
structure and active site distribution. The subsequent electrochemical
characterization of the catalyst shows strong adsorption and poisoning
effect of, in addition to the known Cl-, perchloric anions on the oxygen
reduction reaction (ORR) activity. On the contrary phosphate anions
exhibit negligible poisoning effect on the catalyst activity. At 0.8 V
vs. RHE, the ORR activity of the catalyst is found to decrease in the
order of H3PO4 (8.6 mA mg-1) > H2SO4 (5.3 mA mg-1 ) > HClO4 (3.1 mA mg-1) > HCl (0.7 mA mg-1).
The results suggest potential applications of NPMC in high-temperature
PEMFCs based on phosphoric acid doped polymer membranes, where high
loading platinum catalysts are currently used. As demonstrated in the
low current density range of high-temperature PEMFCs, the catalyst shows
a comparable performance to the Pt/C catalysts.
AB - Non-precious metal catalysts (NPMCs), particularly the type based on carbon-supported FeNx
functionalities (Fe-N-C) are a very promising material for replacing
the rare and costly platinum-based catalysts in polymer electrolyte
membrane fuel cells (PEMFCs). Evaluation of these materials is most
often carried out, like for Pt-based catalysts, in dilute perchloric
acid by assuming its non-adsorbing nature on the active sites. The
assumption is however not true. In this work, a typical Fe-N-C catalyst
was first synthesized by high-pressure pyrolysis in the presence of
carbon support and thoroughly characterized in terms of morphology,
structure and active site distribution. The subsequent electrochemical
characterization of the catalyst shows strong adsorption and poisoning
effect of, in addition to the known Cl-, perchloric anions on the oxygen
reduction reaction (ORR) activity. On the contrary phosphate anions
exhibit negligible poisoning effect on the catalyst activity. At 0.8 V
vs. RHE, the ORR activity of the catalyst is found to decrease in the
order of H3PO4 (8.6 mA mg-1) > H2SO4 (5.3 mA mg-1 ) > HClO4 (3.1 mA mg-1) > HCl (0.7 mA mg-1).
The results suggest potential applications of NPMC in high-temperature
PEMFCs based on phosphoric acid doped polymer membranes, where high
loading platinum catalysts are currently used. As demonstrated in the
low current density range of high-temperature PEMFCs, the catalyst shows
a comparable performance to the Pt/C catalysts.
KW - Oxygen reduction
KW - Catalyst
KW - Fuell cell
KW - Anion
KW - Poison
U2 - 10.1016/j.apcatb.2018.03.056
DO - 10.1016/j.apcatb.2018.03.056
M3 - Journal article
VL - 234
SP - 357
EP - 364
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
SN - 0926-3373
ER -