Journal article
(Invited) Engineering Nanoporous Iridium Microstructures for Stable Oxygen Evolution Electrocatalysis in Acid Media
Meeting abstracts (Electrochemical Society), v MA2020-01(37), pp 1553-1553
01 May 2020
Abstract
Water splitting through PEM electrolysis provides promising route for renewable energy storage and production of high purity hydrogen and oxygen gases. Iridium oxide which is the only stable metal oxide that can evolve oxygen at the anode with reasonable activity is typically alloyed with less expensive transition metals to make high surface area Ir alloy nanostructures for commercially viable oxygen evolution reaction (OER) electrocatalysts. The chemical and morphological stability of such alloy nanostructures at anodic potential in acid is still a major concern for long term electrolysis. Here, we show dealloying as an appropriate method to synthesize free standing high surface area, oxide skinned nanoporous bimetallic Ir (np-Ir) alloys for efficient and stable OER electrolysis in acid media. The metallic core and absence of any binder/support result in low electrode and charge transfer resistance; ultimately giving rise to lower overpotential and much improved ECSA (electrochemically active surface area) normalized current densities compared to traditional IrO
2
electrocatalysts for acidic OER. We also demonstrate with a proper acid concentration in the dealloying electrolyte and a requisite atomic fraction of iridium in the precursor alloy, dealloying gives rise to nanoporous microsheets of core shell Ni-Ir alloy. Compared to the IrO
2
nanoparticles, the nanoporous Ir microstructures offer high carrier mobility because of the interconnected ligamentous structure that provides easy supply of electrons on the iridium oxide surface required to break the water molecule. Overall, the nanoporous Ir obtained through dealloying exhibits low overpotential and stable OER electrolysis in acid media.
Metrics
7 Record Views
Details
- Title
- (Invited) Engineering Nanoporous Iridium Microstructures for Stable Oxygen Evolution Electrocatalysis in Acid Media
- Creators
- Swarnendu ChatterjeeJoshua David Snyder
- Publication Details
- Meeting abstracts (Electrochemical Society), v MA2020-01(37), pp 1553-1553
- Publisher
- Institute of Physics (IOP)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemical and Biological Engineering
- Other Identifier
- 991019297061004721