IrO2/Ir Composite Nanoparticles (IrO2@Ir) Supported on TiNxOy Coated TiN: Efficient and Robust Oxygen Evolution Reaction Catalyst for Water Electrolysis. Issue 4 (13th January 2023)

• Record Type: Journal Article
• Authors: Karade, Swapnil Sanjay; Sharma, Raghunandan; Gyergyek, Saso; Morgen, Per; Andersen, Shuang Ma
• Is Part Of: ChemCatChem. Volume 15:Issue 4(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-13
• Subjects: iridium oxide@iridium -- microwave -- oxygen evolution reaction -- titanium nitride -- titanium oxonitride; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.202201470
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: It is crucial but challenging to reduce the required noble‐metal loading without compromising the catalytic performance of oxygen evolution reaction (OER) catalysts. This study presents a highly active OER catalyst composed of IrO2 with Ir rich surface (IrO2 @Ir) nanoparticles supported over nano TiN coated with TiOx Ny (IrO2 @Ir/TiN). The present approach demonstrates superior OER catalysts with high activity through small, uniformly dispersed IrO2 @Ir nanoparticles, along with high durability owing to robust catalyst support and strong catalyst‐support interaction. The synthesized IrO2 @Ir/TiN with an Ir loading of 40 wt % exhibits a mass‐normalized OER activity of 637 AgIr −1, which is 2.4 times that of the unsupported commercial benchmark IrO2 OER electrocatalyst. The fine nanoparticles and high activity enable significant (∼60 %) reduction in the Ir metal loading required to obtain equivalent OER performance. In addition, when evaluated through an accelerated stress test using potential cycling, the catalyst exhibits outstanding durability (79 % retention) compared to that of the commercial equivalent (66 % retention). The OER activity loss was attributed to the catalyst dissolution (30 % loss) and the catalyst particle growth (70 %), with no measurable loss due to the TiN support corrosion. The development of ultra‐fine IrO2 @Ir nanoparticles and robust ceramic catalyst support significantly improved the Ir utilization and open a new perspective for supported OER catalyst. Abstract : As a catalyst for water electrolysis in acidic media, IrO2 with Ir rich surface (IrO2 @Ir) nanoparticles supported over nano TiN coated with TiOx Ny (IrO2 @Ir/TiN) show high activity and stability. The new catalyst can (i) reduce the required iridium loading to ∼40 % of the state‐of‐the‐art unsupported commercial catalyst and (ii) increase the electrolyzer lifetime.