| Autor: |
Potsi G; Department of Materials Science and Engineering, Cornell University, Ithaca 14853, New York, United States., Tsai YJ; Department of Materials Science and Engineering, Cornell University, Ithaca 14853, New York, United States., Reese A; Department of Chemical and Biomolecular Engineering, Cornell University, Ithaca 14853, New York, United States., Yoon D; Department of Materials Science and Engineering, Cornell University, Ithaca 14853, New York, United States., Hitt JL; Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Kouloumpis A; Department of Materials Science and Engineering, Cornell University, Ithaca 14853, New York, United States., Suntivich J; Department of Materials Science and Engineering, Cornell University, Ithaca 14853, New York, United States., Muller DA; School of Applied and Engineering Physics, Cornell University, Ithaca 14853, New York, United States.; Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca 14853, New York, United States., Mallouk TE; Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States., Giannelis EP; Department of Materials Science and Engineering, Cornell University, Ithaca 14853, New York, United States. |
| Abstrakt: |
The structural characteristics of supports, such as surface area and type of porosity, affect the deposition of electrocatalysts and greatly influence their electrochemical performance in fuel cells. In this work, we use a series of high surface area hierarchical porous carbons (HPCs) with defined mesoporosity as model supports to study the deposition mechanism of Pt nanoparticles. The resulting electrocatalysts are characterized by several analytical techniques, and their electrochemical performance is compared to a state-of-the-art, commercial Pt/C system. Despite the similar chemical composition and surface area of the supports, as well as similar amounts of Pt precursor used, the size of the deposited Pt nanoparticles varies, and it is inversely proportional to the mesopore size of the system. In addition, we show that an increase in the size of the catalyst particles can increase the specific activity of the oxygen reduction reaction. We also report on our efforts to improve the overall performance of the above electrocatalyst systems and show that increasing the electronic conductivity of the carbon support by the addition of highly conductive graphene sheets improves the overall performance of an alkaline fuel cell. |
