TY - JOUR
T1 - Corrosion resistance and acidic ORR activity of pt-based catalysts supported on nanocrystalline alloys of molybdenum and tantalum carbide
AU - Hamo, Eliran R.
AU - Tereshchuk, Polina
AU - Zysler, Melina
AU - Zitoun, David
AU - Natan, Amir
AU - Rosen, Brian A.
N1 - Publisher Copyright:
© 2019 The Electrochemical Society.
PY - 2019
Y1 - 2019
N2 - Cathode catalysts in polymer electrolyte membrane fuel cells (PEMFCs) are often supported by carbon, which is susceptible to corrosion at operating potentials. Transition metal carbides (TMCs) are a class of material that could be used as catalyst supports to replace carbon as they are electrically conductive and can be resistant to corrosion. TMCs which show promising activity for the oxygen reduction reaction (ORR) have been shown to suffer from oxidation and dissolution, whereas corrosion-resistant carbides tend to have significantly lower ORR activities. Here we used co-reduction carburization to synthesized alloys of Mo2C and TaC with the aim of designing a carbide support that was both active and corrosion resistant. The addition of 15 mol% Ta to the precursor mixture used to synthesize the alloy support increased the corrosion potential by nearly 150 mV and decreased the corrosion current to 16% of that observed in the Ta-free support. While Ta-alloyed Mo2C supports had reduced ORR activity compared to their Ta-free counterparts, the Ta-alloyed supports performed favorably when compared to Vulcan XC-72. We show that further improvements to alloy-carbide based supports can be achieved by modulating the structure of the catalyst particles from Pt to Pt3Ni. Furthermore, density functional theory (DFT) calculations can be used to predict oxygen binding and corrosion resistance in digitally designed alloy carbides.
AB - Cathode catalysts in polymer electrolyte membrane fuel cells (PEMFCs) are often supported by carbon, which is susceptible to corrosion at operating potentials. Transition metal carbides (TMCs) are a class of material that could be used as catalyst supports to replace carbon as they are electrically conductive and can be resistant to corrosion. TMCs which show promising activity for the oxygen reduction reaction (ORR) have been shown to suffer from oxidation and dissolution, whereas corrosion-resistant carbides tend to have significantly lower ORR activities. Here we used co-reduction carburization to synthesized alloys of Mo2C and TaC with the aim of designing a carbide support that was both active and corrosion resistant. The addition of 15 mol% Ta to the precursor mixture used to synthesize the alloy support increased the corrosion potential by nearly 150 mV and decreased the corrosion current to 16% of that observed in the Ta-free support. While Ta-alloyed Mo2C supports had reduced ORR activity compared to their Ta-free counterparts, the Ta-alloyed supports performed favorably when compared to Vulcan XC-72. We show that further improvements to alloy-carbide based supports can be achieved by modulating the structure of the catalyst particles from Pt to Pt3Ni. Furthermore, density functional theory (DFT) calculations can be used to predict oxygen binding and corrosion resistance in digitally designed alloy carbides.
UR - http://www.scopus.com/inward/record.url?scp=85076013351&partnerID=8YFLogxK
U2 - 10.1149/2.0251916jes
DO - 10.1149/2.0251916jes
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AN - SCOPUS:85076013351
SN - 0013-4651
VL - 166
SP - F1292-F1300
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 16
ER -