Publications by authors named "S Kaan OEner"

The interface between electrocatalyst and electrolyte is highly dynamic. Even in absence of major structural changes, the intermediate coverage and interfacial solvent are bias and time dependent. This is not accounted for in current kinetic models.

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Water dissociation (WD, HO → H + OH) is the core process in bipolar membranes (BPMs) that limits energy efficiency. Both electric-field and catalytic effects have been invoked to describe WD, but the interplay of the two and the underlying design principles for WD catalysts remain unclear. Using precise layers of metal-oxide nanoparticles, membrane-electrolyzer platforms, materials characterization, and impedance analysis, we illustrate the role of electronic conductivity in modulating the performance of WD catalysts in the BPM junction through screening and focusing the interfacial electric field and thus electrochemical potential gradients.

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Water electrolysis powered by renewable electricity produces green hydrogen and oxygen gas, which can be used for energy, fertilizer, and industrial applications and thus displace fossil fuels. Pure-water anion-exchange-membrane (AEM) electrolyzers in principle offer the advantages of commercialized proton-exchange-membrane systems (high current density, low cross over, output gas compression, etc.) while enabling the use of less-expensive steel components and nonprecious metal catalysts.

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In this study, we have taken advantage of a pulsed CO electroreduction reaction (CORR) approach to tune the product distribution at industrially relevant current densities in a gas-fed flow cell. We compared the CORR selectivity of Cu catalysts subjected to either potentiostatic conditions (fixed applied potential of -0.7 V) or pulsed electrolysis conditions (1 s pulses at oxidative potentials ranging from = 0.

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Article Synopsis
  • * The researchers designed a BPM electrolyzer to analyze the kinetics of WD and found a correlation between the WD activity of metal nanoparticles and their efficiency in hydrogen production under alkaline conditions.
  • * By using a combination of metal-oxide WD catalysts optimized for different pH layers, they achieved a WD process with low overpotentials and demonstrated effective BPM electrolyzers that can operate at high currents with a low total voltage requirement.
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