Iridium Nanoparticles on Ceria for Hydrogen Evolution Reaction in Acidic Medium

Akbayrak M., Önal A. M.

3 rd International HydrogenEnergy Congress&Exhibitions, Ankara, Turkey, 14 - 16 June 2021, pp.143

  • Publication Type: Conference Paper / Summary Text
  • City: Ankara
  • Country: Turkey
  • Page Numbers: pp.143
  • Middle East Technical University Affiliated: Yes

Abstract

Ir nanoparticles were successfully prepared on the ceria surface and tested for hydrogen evolution reaction (HER) in 0.5 M H2SO4 solution. Ir/CeO2 was found to exhibit excellent activity and superior stability. According to the polarization curve, onset potential (η0) and overpotential (η@10 mA.cm-2  ) of Ir/CeO2 were found as -13 and -23 mV, respectively, which are lower than the values obtained for commercial 10% Pt/C catalyst. Moreover, Ir/CeO2 provides a low Tafel slope (38.7 mV.dec-1), high turnover frequency (1.95 @100 mV) and high exchange current density (j0= 2.69 mA.cm-2). In addition, the electrocatalytic stability test shows that Ir/ CeO2 exhibits outstanding stability for HER in 0.5 M H2SO4 even after 20 000 CV cycles without any noticeable change in the Tafel slope. Considering the high stability, facile preparation method, and low iridium loading (2.44 wt%), binder-free Ir/CeO2 is a promising electrocatalyst for hydrogen evolution from water splitting.

Keywords: Electrocatalyst, Iridium, Ceria, Hydrogen evolution reaction, Water splitting