Highly active nano-sized iridium catalysts: synthesis and operando spectroscopy in a proton exchange membrane electrolyzer.

ABSTRACT: A stable and cost effective oxygen evolution reaction (OER) catalyst is crucial for the large-scale market penetration of proton exchange membrane (PEM) water electrolyzers. We show that the synthesis of iridium nanoparticles in either low purity ethanol or water, or in the absence of a surfactant, is detrimental to the electrocatalytic properties of the materials. Adding NaBH₄ in excess improves the purity of the catalyst enhancing the OER activity up to 100 A g_Ir^-1 at 1.51 V vs. RHE, the highest value reported so far for high purity Ir nanoparticles. The measured OER activity correlates with the capacitive current rather than with the charge corresponding to the Ir^III/Ir^IV oxidation peak. Operando near-ambient pressure

SUBMITTER: Lettenmeier P 

PROVIDER: S-EPMC5934821 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature