Bifunctional Pt–Ir nanoparticle catalysts for oxygen reduction and evolution reactions: investigating the influence of surface composition on the catalytic properties

Abstract

Unitized regenerative fuel cells (URFCs) can provide renewable, clean energy and hydrogen but require efficient bifunctional catalysts for oxygen reduction (ORR) and evolution reactions (OER). In this study, we present...

Catalyst Interaction in Unitized Regenerative Fuel Cells

“…This observation can be explained by the fact that the (100) domains exhibit higher energy, making them preferred sites for IrO 2 deposition. 12 Thus, as the IrO 2 content increases, a larger portion of Pt (100) seems to be covered with IrO 2 , thereby impeding its participation in CO oxidation. The complete absence of the CO stripping voltammetry peaks for the 1:9 ratio may be explained by the comparatively large quantity of IrO 2 , which is inactive for CO oxidation.…”

“…[9][10][11] A range of different types were studied, from physical mixtures to Pt-Ir alloys or composites of Pt and Ir oxides. [12][13][14][15][16][17] Some studies investigated and analyzed the optimal Ir/Pt ratio for the bifunctional catalyst either via rotating disk electrode (RDE) or in a cell setup. Regmi et al evaluated first the ratio under discrete EL and FC conditions before bringing the catalyst into the membrane electrode assembly (MEA) for the PEM-URFC.…”