Anion Exchange Membrane Fuel Cells: Enhanced Alkaline Hydrogen Oxidation Activity of Ceria-palladium Nanoparticle Catalysts

Anion exchange membrane fuel cells (AEMFCs) offer several important advantages with respect to proton exchange membrane fuel cells (PEMFCs), which can contribute to overcoming the high cost of fuel cell systems that has largely slowed large-scale implementation. The poor kinetics of the hydrogen oxidation reaction (HOR) and other limitations in performance such as the instability of membranes have stalled AEMFC development. Replacing Pt at the anode with a cheaper catalyst that has also enhanced activity for the HOR is a key objective for those working in the field of AMFCs. We recently reported a new class of HOR catalyst based on Pd nanoparticles supported on carbon and CeO2 that allowed us to achieve 0.5 W cm-2 peak power density in a Pt-free AEMFC.1,2 In this presentation, we report further enhanced HOR kinetics due to a maximized Pd-CeO2 contact between these two phases on the nanoscale. To date, this is the only alternative non Pt HOR catalyst yet reported that matches state of the art fuel cell performances (> 1 W cm-2). We present here a reproducible synthesis (on the gram scale) that consists of the addition of CeO2 to carbon using an organometallic precursor followed by Pd deposition. With this catalyst more than 1.4 W cm-2 peak power density in fuel cell testing is achieved.