Nevenka R Elezovic
University of Belgrade, Serbia
Title: Noble metal based nanostructures for zero emission energy production-carbon based vs. carbon free catalysts supports, advantages and disadvantages
Biography
Biography: Nevenka R Elezovic
Abstract
Platinum based nanoparticles on high surface area carbon (commercially named Vulcan XC 72 or Ketjen Black) are state of the art materials for low temperature fuel cells application – high efficiency environmental friendly power sources. These catalysts have acceptable high activity for commercial use; however the stability is still big challenge to overcome, to achieve proper durability and long-life costs acceptable for practical purpose. The other big challenge is high oxygen reduction overpotential and its slow kinetics causing unacceptable power loss. Namely, we have synthesized Pt based nano catalysts on different metal oxide based supports (Ti, Sn, W based oxides) and characterized its activity and stability for oxygen reduction reaction. The supports were doped by several percent of Nb and Ru (5-10%) to achieve sufficient conductivity. The synthesized nanocatlysts were characterized by X-ray Diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Electron Energy Loss Spectroscopy (EELS), X-Ray Photoelectron Spectroscopy (XPS), as well as by electrochemical techniques and Accelerated Stability Testing. The results confirmed very high activity and stability, if compared to commercial Vulcan XC 72 supported catalysts with the same Pt loading.