Abstract
The synthesis process, reactive spray deposition technology (RSDT), utilized a jet-flame to produce Pt nanoparticles. The RSDT process bypasses traditional wet chemical routes by simultaneously nucleating the catalyst on a support and sequential deposition of catalyst layer via the gas phase. Pt nanoparticles were attached, in the process gas during the time-of-flight, to the surface of several supports. The supports show promising corrosion resistance under the cathode conditions of a proton exchange membrane fuel cell (PEMFC). The supported Pt catalysts were then studied in regards to structure, stability and electrochemical behavior toward the oxygen reduction reaction (ORR) in perchloric acid. Transmission electron microscopy studies showed that the average Pt particle diameter is ∼2.5 nm. The average diameter and distribution of the Pt particles are independent of the support type and a high degree of catalyst dispersion has been achieved on all supports. The greatest surface area and electrochemical mass activity were obtained using Vulcan XC-72R, while a graphitized carbon support produced the highest specific activity. Based on X-ray photoelectric spectroscopy (XPS) measurements, approximately 30% of the surface of the Pt particles is comprised of Pt 2+. This oxide coverage does not extend into the bulk and is below the detection limits of X-ray diffraction (XRD). The electrochemical reduction of oxygen exhibits a typical Tafel slope of -65 to -71 mV/dec.
| Original language | English |
|---|---|
| Pages (from-to) | 632-655 |
| Number of pages | 24 |
| Journal | Electrochimica Acta |
| Volume | 107 |
| DOIs | |
| State | Published - 2013 |
| Externally published | Yes |
Funding
The authors would like to acknowledge financial support from the University of Connecticut's Department of Materials Science and Engineering , the Connecticut Clean Energy Fund Professor in Sustainable Energy chair , and the Department of Energy Small Business Technology Transfer (STTR) program (Grant # DE-SC0009213 ). Justin Roller thanks the Department of Education for a GAANN Fellowship (Grant # P200A090347). The machine-shop services of Mark Drobney (UConn Technical Services) are greatly appreciated. M.J.A.-J. and C.B.C. thank David Bell and Adam Graham for assistance and access to the electron microcopy facilities at the Harvard Center for Nanoscale Systems (CNS) and Eric Stach and Dong Su for assistance and access at the Center for Functional Nanomaterials at BNL. The authors would also like to thank Dr. Scott Misture at Alfred University for X-ray diffraction measurements and helpful discussions.
| Funders | Funder number |
|---|---|
| Connecticut Clean Energy Fund Professor in Sustainable Energy | DE-SC0009213 |
| Department of Education | P200A090347 |
| University of Connecticut's Department of Materials Science and Engineering |
Keywords
- Electrode stability
- Flame synthesis
- Oxygen reduction reaction
- PEM fuel cell
- Rotating disk electrode
