Comparative study of different carbon-supported Fe2O3-Pt catalysts for oxygen reduction reaction.

One of the challenges in electrocatalysis is the adequate dispersion of the catalyst on an appropriate porous support matrix, being up to now the most commonly used the carbon-based supports. To overcome this challenge, carbon supports must first be functionalized to guide the catalyst's nucleation, thereby, improving the dispersion and allowing the use of smaller amount of the catalyst material to achieve a higher electrochemically active surface area. This study present the effect of functionalized Vulcan carbon XC72 (FVC) and functionalized Black Pearl carbon (FBPC) as supports on the catalytic activity of decorated Fe2O3 with Pt. Both carbons were functionalized with HNO3 and subsequently treated with ethanolamine. Fe2O3 nanoparticles were synthesized by chemical reduction and decorated with platinum by epitaxial growth. Pt and Fe2O3 structural phases were identified by XRD and XPS; the Pt content was measured by XPS, and results showed to a high Pt content in Fe2O3-Pt/FBPC. TEM micrographs reveal nanoparticles with an average size of 2 nm in both supported catalysts. The Fe2O3-Pt/FVC catalyst presents the highest specific activity and mass activity, 0.21 mA cm-2Pt and 140 mA mgPt-1, respectively, associated to the appropriate distribution of platinum on the Fe2O3 nanoparticles.