Electrochemical performance of fuel cell catalysts prepared by supercritical deposition: Effect of different precursor conversion routes

Bozbag S. E., Gumusoglu T., Yilmazturk S., Ayala C. J., Aindow M., Deligoz H., ...Daha Fazla

JOURNAL OF SUPERCRITICAL FLUIDS, cilt.97, ss.154-164, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 97
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1016/j.supflu.2014.08.014
  • Dergi Adı: JOURNAL OF SUPERCRITICAL FLUIDS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.154-164
  • İstanbul Üniversitesi Adresli: Evet

Özet

Supercritical deposition (SCD) is used to prepare carbon-supported Pt nanoparticles as electrocatalysts for proton exchange membrane fuel cells (PEMFCs). Dimethyl(1,5-cyclooctadiene)platinum(II) (Pt(cod)me(2)) is adsorbed from supercritical carbon dioxide (scCO(2)) solutions onto Vulcan VX-72 at 13.2 MPa and 50 degrees C. The adsorbed metal precursor is converted to its metal form via three different routes: thermal conversion in N-2 at ambient pressure (route 1), thermal conversion in scCO(2) (route 2), or chemical conversion in H-2 at ambient pressure (route 3). Sequential SCD is used in routes 1 and 3. The mean diameters of the synthesized Pt nanoparticles are smallest for route 1 and largest for route 3. Nano-scale morphology of the electrocatalysts is characterized using transmission electron microscopy (TEM), revealing narrower Pt particle size distributions for the catalyst prepared via route 1 than for those synthesized by routes 2 and 3. Electrocatalyst prepared using route 1 showed the best performance both in specific activity (measured via cyclic voltammetry) and in PEMFC tests among electrocatalysts prepared using different routes. (C) 2014 Elsevier B.V. All rights reserved.

Supercritical deposition (SCD) is used to prepare carbon-supported Pt nanoparticles as electrocatalysts for proton exchange membrane fuel cells (PEMFCs). Dimethyl(1,5-cyclooctadiene)platinum(II) (Pt(cod)me(2)) is adsorbed from supercritical carbon dioxide (scCO(2)) solutions onto Vulcan VX-72 at 13.2 MPa and 50 degrees C. The adsorbed metal precursor is converted to its metal form via three different routes: thermal conversion in N-2 at ambient pressure (route 1), thermal conversion in scCO(2) (route 2), or chemical conversion in H-2 at ambient pressure (route 3). Sequential SCD is used in routes 1 and 3. The mean diameters of the synthesized Pt nanoparticles are smallest for route 1 and largest for route 3. Nano-scale morphology of the electrocatalysts is characterized using transmission electron microscopy (TEM), revealing narrower Pt particle size distributions for the catalyst prepared via route 1 than for those synthesized by routes 2 and 3. Electrocatalyst prepared using route 1 showed the best performance both in specific activity (measured via cyclic voltammetry) and in PEMFC tests among electrocatalysts prepared using different routes.