Synthesis and characterization of Pd nanocatalyst at W based support for low temperature fuel cells application

Synthesis and characterization of Pd nanocatalyst at W based support for low temperature fuel cells application N.R.Elezovic1, M.Krstajic Pajic2, P.Zabinski3, P. Ercius4, V.R.Radmilovic5,6, N.V. Krstajic6 1Institute for... [ view full abstract ]

Synthesis and characterization of Pd nanocatalyst at W based support for low temperature fuel cells application

N.R.Elezovic¹, M.Krstajic Pajic², P.Zabinski³, P. Ercius⁴, V.R.Radmilovic^5,6, N.V. Krstajic⁶

¹Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, Belgrade, Serbia, 

²Institute for Chemistry Technology and Metallurgy University of Belgrade,Serbia, 

³AGH University of Science and Technology, Faculty of Non-Ferrous Metals, Al. Mickiewicza 30,30-059 Krakow, Poland

⁴National Center for Electron Microscopy, LBNL University of California, Berkeley, CA, USA

⁵ Serbian Academy of Sciences and Arts, Knez Mihailova 35,  Belgrade, SERBIA

⁶Faculty of Technology and Metallurgy University of Belgrade

Introduction

Pt based nanoparticles supported on high surface area carbon (Vulcan XC 72 or Ketjen Black) are state of the art materials for low temperature fuel cells application. These catalysts have proper activity, however the stability is still a big challenge to overcome, to achieve durability and long life costs acceptable for practical purpose. The other big challenge is high oxygen reduction overpotential and slow kinetics, causing unacceptable power loss.

Methods and Results

In this research we have synthesized novel Pd based nanocatalyst onto core-shell tungsten based support and characterized its activity and stability for oxygen reduction reaction. The support was prepared by polycondensation of resorcinol and formaldehyde from ammonium metatungstate in the presence cetyltrimethylammonium bromide surfactant. Pd nanocatalyst was synthesized by borohydride reduction. All materials were characterized by X-ray Diffraction, High Resolution Transmission Electron Microscopy, Electron Energy Loss Spectroscopy, X-ray Photoelectron Spectroscopy and electrochemical techniques: cyclic voltammetry and Accelerated Stability Testing (AST). The results confirmed high activity and stability of Pd nanocatalyst, compared to Pd/XC with the same noble metal loading. ORR activity expressed in terms of onset and half wave potential, as well as kinetic current density at 0.85 V vs RHE were comparable to Pt based catalysts. These results were assigned to the catalyst high surface area and consequently high noble metal utilization. AST proved high catalyst’s durability, especially in alkaline electrolyte.

Acknowledgements: This work was supported by Ministry of Education, Science and Technological Development, Republic of Serbia, Contract No. 172054. The authors would like to acknowledge networking support by the COST Action MP1407.