A5102004696- Fuel Cells and Related Materials
- Electrocatalysts for Energy Conversion
- Advanced battery technologies research
- Conducting polymers and applications
- Hybrid Renewable Energy Systems
- Membrane-based Ion Separation Techniques
- Advanced Battery Materials and Technologies
- Advancements in Solid Oxide Fuel Cells
- Fluorine in Organic Chemistry
- Asymmetric Synthesis and Catalysis
- Carbon Nanotubes in Composites
- Supercapacitor Materials and Fabrication
- Ionic liquids properties and applications
- Phase Equilibria and Thermodynamics
- Chemical Synthesis and Reactions
- Asymmetric Hydrogenation and Catalysis
- Advanced Battery Technologies Research
- Oxidative Organic Chemistry Reactions
- Synthesis and Reactions of Organic Compounds
- Extraction and Separation Processes
- Carbon dioxide utilization in catalysis
- Electrospun Nanofibers in Biomedical Applications
- Advanced Sensor and Energy Harvesting Materials
- Metal and Thin Film Mechanics
- Chemical Synthesis and Analysis
Los Alamos National Laboratory
2017-2025
Pusan National University
2021-2024
Government of the United States of America
2022
Los Alamos Medical Center
2018-2020
Rensselaer Polytechnic Institute
2015-2018
Inha University
1997-2011
Korea University
2005-2009
Pukyong National University
2004-2007
Soonchunhyang University
2002-2005
Ajou University
1996
A new design concept for ion-conducting polymers in anion exchange membranes (AEMs) fuel cells is proposed based on structural studies and conformational analysis of their effect the properties AEMs. Thermally, chemically, mechanically stable terphenyl-based with pendant quaternary ammonium alkyl groups were synthesized to investigate varying arrangement polymer backbone cation-tethered chains. The results demonstrate that microstructure morphology these polymeric significantly influence ion...
High-performance of polyaromatic alkaline membrane fuel cells was achieved with a polyfluorene ionomer minimizing adsorption on hydrogen oxidation catalysts.
Hydrogen holds great promise as a clean energy resource to help the global carbon-free goal. Green hydrogen production from renewable energy-powered water electrolysis can decarbonize hard-to-abate industries and transport applications. Ion-exchange membranes are an essential component of membrane-based electrolysis, enabling high efficiency through zero-gap configuration. While perfluorosulfonic acids standard polymer electrolyte membrane material, research efforts for alternatives have...
The catalytic enantioselective electrophilic fluorination promoted by quaternary ammonium salt from cinchonine as a phase-transfer catalyst is described. Treatment of β-keto esters with N-fluorobenzenesulfonimide the fluorine source under mild reaction conditions afforded corresponding α-fluoro in exellent yields good to moderate enantiomeric excesses
The performance of anion exchange membrane fuel cells (AEMFCs) employing Pt or PtRu electrocatalyst and ionomers with different polyaromatic backbones is correlated the density functional theory (DFT)-calculated adsorption energies ionomer fragments on metal surfaces. AEMFCs tested in this work significantly changes depending backbone structure type catalyst used at anode. For same anode catalyst, decreases order poly(fluorene) > poly(p-biphenyl alkylene) poly(terphenyl alkylene)s, which...
The durability of alkaline anion exchange membrane (AEM) electrolyzers is a critical requirement for implementing this technology in cost-effective hydrogen production. Here, we report that the electrochemical oxidation adsorbed phenyl group (found ionomer) on oxygen evolution catalysts produces phenol, which may cause performance deterioration AEM electrolyzers. In-line 1H NMR kinetic analyses model organic cation electrolyte shows catalyst type significantly impacts rate at an potential....
Alkaline stability of anion exchange membranes (AEMs) is an essential requirement for the practical application alkaline membrane fuel cells. In this study, we investigate Diels–Alder polyphenylenes (DAPPs) under various testing conditions. Structural analysis and properties DAPPs indicated that different chemical structural changes quaternized occur depending on test Benzyltrimethylammonium-functionalized degraded rapidly via nucleophilic benzyl substitution a relatively mild condition at...
An asymmetric anion exchange membrane fuel cell enables high performance and operational durability under low RH conditions.
Hydrogen production through anion-exchange membrane water electrolyzers (AEMWEs) offers cost advantages over proton-exchange counterparts, mainly due to the good oxygen evolution reaction (OER) activity of platinum-group-metal-free catalysts in alkaline environments. However, electrochemical oxidation ionomers at OER catalyst interface can decrease local electrode pH, which limits AEMWE performance. Various strategies single-cell-level have been explored address this issue. This work reviews...
Catalytic enantioselective alkylation promoted by a quaternary ammonium salt from cinchonine as phase transfer catalyst is described. Treatment of cyclo beta-keto esters with alkyl halide under mild reaction conditions afforded the corresponding alpha-alkylated in moderate to excellent yields high enantiomeric excesses
Aromatic rings of poly(styrene-b-(ethylene-r-butylene)-b-styrene) triblock copolymer (SEBS) were functionalized with various acid functional groups for proton exchange membrane (PEM) applications. Three different (fluoroalkylsulfonic acid, arylsulfonic and arylphosphonic acid) introduced into SEBS via borylation aromatic C–H bonds Suzuki coupling reactions. The incorporation side selectively the polystyrene block created nanometer-scale phase separated morphology composed hydrophilic...
Small changes in anode ionomeric binder structure may bring significant performance and durability improvement of anion-exchange membrane fuel cells.
Abstract Ionomer thin‐films (i.e., 20–100 nm) on supports serve as model systems to understand ionomer‐catalyst interfacial behavior well the confinement‐driven deviation in properties from bulk membranes. While ionomer have been examined for proton exchange ionomers, thin‐film of anion ionomers (AEIs) remain largely unexplored. More importantly, delineating convoluted impact chemistry and confinement morphology hydration is interest advancing field functional ionic interfaces. In this work,...
We investigated how chemical structure and physical properties of polymer electrolytes affect performance durability anion exchange membrane water electrolyzers.
Abstract Carbon‐based materials are extensively used in fuel cell applications due to their crucial role maintaining high performance. Particularly, carbon black (CB) stands out as a preferred electrode material for cells, owing its electrical conductivity and large surface area. This review focuses on the functionalization of CB use support Pt‐based catalysts proton exchange membrane cells. Functionalization strategies include oxidation, covalent functionalization, well polymer grafting or...
Anion-exchange membrane electrolyzer cells (AEMECs) are one of the most promising technologies for carbon-neutral hydrogen production. Over past few years, performance and durability AEMECs have substantially improved. Herein, we report an engineered liquid/gas diffusion layer (LGDL) with tunable pore morphologies that enables high AEMECs. The comparison a commercial titanium foam in indicated LGDL thin-flat straight-pore structures significantly improved interfacial contacts, mass...
This study presents the validation of protocols for measuring ion exchange capacity (IEC) and alkaline stability anion membranes (AEMs) low-temperature water electrolysis. While are often tested within individual laboratories, their results across multiple laboratories with varying equipment, environmental conditions, personnel qualification remain unverified. The involved Los Alamos National Laboratory (LANL), Renewable Energy (NREL), University Oregon (UO) using same commercially available...