Development of Advanced non-Pt Electrocatalysts for Anion Exchange Membrane Fuel Cells

Elena S. Davydova, Chemical Engineering , Technion , Haifa, Israel
Dario R. Dekel, Chemical Engineering , Technion , Haifa, Israel

Recent developments in anion exchange membranes (AEMs) [1] have contributed to the growing interest in anion exchange membrane fuel cells (AEMFCs). Power densities as high as 1.2 Wcm-2 have been reported for AEMFCs with O2 supplied cathodes [2] and 0.5 Wcm-2 for air-supplied cathodes, Pt/C used as the catalyst on the both sides [3]. As regarding Pt-free AEMFC, maximum power density of 500 mWcm-2 was achieved [4]. The performances of AEMFC with Pt-free cathode catalysts span between ~50 and ~190 mWcm-2 [5].
The aim of the work is the development platinum-free electrocatalysts for the hydrogen oxidation reaction (HOR) in the alkaline medium of AEMFCs.
Electrocatalysis of the HOR in alkaline media is analyzed for different types of materials, including Pt-, Pd-, Rh-, Ir, Ru and Ni-based catalysts. More than 160 values of hydrogen binding energy for 18 different elements of Periods 4–6 are collected. The pathways and mechanisms of the HOR for different types of materials in the base solutions is discussed. Analysis of the specific and mass catalytic activity values, as well as exchange current density values, for a variety of catalysts is provided.
Our results on the investigation of the catalysts Ni/C-N, Ru/C and RuNi/C-N (C and C-N are non-modified and nitrogen-doped carbon black), synthesized via chemical reduction or hydrothermal method, in the HOR in 1 M KOH are presented. The catalysts are characterized using rotating disc electrode, cyclic voltammetry, electrochemical impedance spectroscopy, BET, XRD and XPS methods.

[1] Energy Environ. Sci. 7 (2014) 3135.
[2] Energy Environ. Sci. 8 (2015) 177.
[3] Int. J. Hydrogen Energy 37 (2012) 11912.
[4] Angew. Chem. Int. Ed. 55 (2016) 6004.
[5] Rus. J.Electrochem. 52 (2016) 193.

The work was partially funded by GTEP.