Alkaline Ethanol Oxidation Reaction on Carbon Supported Ternary PdNiBi Nanocatalyst using Modified Instant Reduction Synthesis Method

Bernd Cermenek; Boštjan Genorio; Thomas Winter; Sigrid Wolf; Justin G Connell; Michaela Roschger; Ilse Letofsky-Papst; Norbert Kienzl; Brigitte Bitschnau; Viktor Hacker

doi:10.1007/s12678-019-00577-8

Alkaline Ethanol Oxidation Reaction on Carbon Supported Ternary PdNiBi Nanocatalyst using Modified Instant Reduction Synthesis Method

Electrocatalysis (N Y). 2020;11(2):203-214. doi: 10.1007/s12678-019-00577-8. Epub 2020 Jan 3.

Affiliations

¹ Institute of Chemical Engineering and Environmental Technology, Fuel Cell Systems Group, Graz University of Technology, NAWI Graz, Inffeldgasse 25/C, 8010 Graz, Austria.
² Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia.
³ Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 USA.
⁴ Institute for Electron Microscopy and Nanoanalysis and Center for Electron Microscopy, Graz University of Technology, NAWI Graz, Steyrergasse 17, 8010 Graz, Austria.
⁵ Bioenergy 2020+ GmbH, Inffeldgasse 21/B, 8010 Graz, Austria.
⁶ Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.

Abstract

Direct ethanol fuel cells (DEFC) still lack active and efficient electrocatalysts for the alkaline ethanol oxidation reaction (EOR). In this work, a new instant reduction synthesis method was developed to prepare carbon supported ternary PdNiBi nanocatalysts with improved EOR activity. Synthesized catalysts were characterized with a variety of structural and compositional analysis techniques in order to correlate their morphology and surface chemistry with electrochemical performance. The modified instant reduction synthesis results in well-dispersed, spherical Pd₈₅Ni₁₀Bi₅ nanoparticles on Vulcan XC72R support (Pd₈₅Ni₁₀Bi₅/C^(II-III)), with sizes ranging from 3.7 ± 0.8 to 4.7 ± 0.7 nm. On the other hand, the common instant reduction synthesis method leads to significantly agglomerated nanoparticles (Pd₈₅Ni₁₀Bi₅/C^(I)). EOR activity and stability of these three different carbon supported PdNiBi anode catalysts with a nominal atomic ratio of 85:10:5 were probed via cyclic voltammetry and chronoamperometry using the rotating disk electrode method. Pd₈₅Ni₁₀Bi₅/C^(II) showed the highest electrocatalytic activity (150 mA⋅cm^-2; 2678 mA⋅mg^-1) with low onset potential (0.207 V) for EOR in alkaline medium, as compared to a commercial Pd/C and to the other synthesized ternary nanocatalysts Pd₈₅Ni₁₀Bi₅/C^(I) and Pd₈₅Ni₁₀Bi₅/C^(III). This new synthesis approach provides a new avenue to developing efficient, carbon supported ternary nanocatalysts for future energy conversion devices. Graphical AbstractThe modified instant reduction method for synthesis of ternary Pd₈₅Ni₁₀Bi₅/C^(II) nanocatalyst using Vulcan XC72R as carbon support initiates an agglomeration reduction, provides low average particle size, and enables enhanced activity for the alkaline ethanol oxidation reaction (EOR) compared to the common instant reduction method and to a commercial Pd/C catalyst.

Keywords: Alkaline direct ethanol fuel cell; Ethanol oxidation reaction activity; Modified instant reduction synthesis method; Morphology; Pd85Ni10Bi5 nanocatalyst; Structure.