Highly Active, Durable Dispersed Iridium Nanocatalysts for PEM Water Electrolyzers

Content Provider	United States Department of Energy Office of Scientific and Technical Information (OSTI.GOV)
Author	Zhao, Shuai Stocks, Allison Rasimick, Brian More, Karren Xu, Hui
Organization	Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Abstract	One of the primary challenges for proton exchange membrane (PEM) electrolyzers is the sluggish kinetics of the oxygen evolution reaction (OER) at the anode, which requires the use of precious metals or metal oxides, such as iridium (Ir) or iridium oxide (IrOx), as the OER catalyst. This study introduces a one-pot surfactant-free polyol reduction method to disperse iridium nanoparticles on a tungsten doped titanium oxide (WxTi1-xO2) support. The polyol reduction approach for the Ir/WxTi1-xO2 catalyst synthesis was systematically investigated to determine the influence of synthesis parameters on the catalysts’ physical properties, and its electrochemical activity and durability. The most promising synthesized catalyst with 38 wt% Ir (Ir38%/WxTi1-xO2) demonstrated five times higher mass activity than an Ir-black baseline (the industry standard catalyst) based on rotating-disk electrode (RDE) studies. When tested in a real water electrolyzer system, the synthesized catalyst enabled the Ir loading to be lowered by an order of magnitude while retaining a similar electrolyzer performance found for the baseline Ir-black catalyst. In conclusion, the Ir38%/WxTi1-xO2 catalyst also demonstrated remarkable stability, e.g., only small voltage (<20 mV) increase was observed during a 1200-hour durability test at a constant current density of 1500 mA/cm2.
Sponsorship	USDOE Office of Energy Efficiency and Renewable Energy (EERE) USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5)
Related Links	https://www.osti.gov/biblio/1460216
Starting Page	F82
Ending Page	F89
Page Count	8
File Format	PDF
ISSN	00134651
DOI	10.1149/2.0981802jes
Journal	Journal of the Electrochemical Society
Volume Number	165
Issue Number	2
Language	English
Publisher	The Electrochemical Society
Publisher Date	2018-01-01
Publisher Department	Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publisher Place	United States
Access Restriction	Open
Subject Keyword	INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY Oxygen Evolution Catalyst Proton Exchange Membrane Water Electrolyzer
Content Type	Text
Resource Type	Article
Subject	Surfaces, Coatings and Films Materials Chemistry Renewable Energy, Sustainability and the Environment Electronic, Optical and Magnetic Materials Condensed Matter Physics Electrochemistry