A5078167692- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Spectroscopy and Quantum Chemical Studies
- CO2 Reduction Techniques and Catalysts
- Catalytic Processes in Materials Science
- Oxidative Organic Chemistry Reactions
- Electrochemical sensors and biosensors
- Catalysts for Methane Reforming
- Analytical Chemistry and Sensors
- Iron oxide chemistry and applications
- Catalysis and Hydrodesulfurization Studies
- Advanced battery technologies research
- Advanced Memory and Neural Computing
University of Delaware
2019-2024
Although electrochemical hydrogen evolution and oxidation are arguably the best-understood reactions in electrocatalysis, anomalous effect of pH on reaction kinetics has defied simple explanation for decades. This longstanding puzzle exposes gaps fundamental understanding electrocatalysis by showing that singular adsorption descriptors (e.g., binding energy) cannot describe kinetic effects across electrolytes. In this Perspective, we discuss strengths shortcomings energies as HER/HOR...
Electrolyte cations affect the activity of surface-mediated electrocatalytic reactions; however, understanding modes interaction between and reaction intermediates remains lacking. We show that larger alkali metal (excluding thickness hydration shell) promote electrochemical CO reduction on polycrystalline Cu surfaces in alkaline electrolytes. Combined reactivity situ surface-enhanced spectroscopic investigations changes to interfacial electric field strength cannot solely explain trend with...
In situ/operando surface enhanced infrared and Raman spectroscopies are widely employed in electrocatalysis research to extract mechanistic information establish structure-activity relations. However, these two spectroscopic techniques more frequently isolation than combination, owing the assumption that they provide largely overlapping regarding reaction intermediates. Here we show tend probe different subpopulations of adsorbates on weakly adsorbing surfaces while providing similar...
The transition to renewable energy and variability in solar wind production rates necessitates the use of an intermediary, well suited acid based electrolyzer fuel cell devices idealized hydrogen economy. However, high material costs have motivated a alkaline devices, exposing pH dependent performance losses on traditionally ideal catalysts. Understanding reduced oxidation evolution (HOR/HER) activity platinum with increasing is essential from both fundamental electrocatalysis perspective...
Abstract Understanding the pH dependent shift of oxidation peak underpotential deposited hydrogen (H upd ) in cyclic voltammograms on Pt surface is significance terms both fundamentals electrochemistry and rational design catalysts for oxidation/evolution reactions (HOR/HER). In this work, we provide compelling evidence that H surfaces driven by structure interfacial water rather than specific adsorption cations electrode surface. Combined voltammetric enhanced spectroscopic investigations...
Terephthalic acid is conventionally synthesized through the AMOCO process under harsh conditions, making milder electrosynthesis routes desirable. Electrooxidation of p-xylene has been demonstrated but degree oxidation limited, resulting in low terephthalic yields. Here, we demonstrate a with two electrochemical steps enabling complete into acid. The first step achieves C-H activation using electrochemically generated bromine as mediator, while second does alcohol 1,4-benzenedimethanol...
A grand challenge in electrochemistry is to understand and promote electrochemical processes by exploring exploiting the interface. Herein, we promoted hydrogen evolution oxidation reactions (HER/HOR) of platinum (Pt) base introducing N-methylimidazoles into Pt-water In situ spectroscopic characterization interface together with Quantum Mechanics computations showed that this promotion caused facilitating diffusion hydroxides across holding second layer water close Pt surfaces. We...
A grand challenge in electrochemistry is to understand and promote electrochemical processes by exploring exploiting the interface. Herein, we promoted hydrogen evolution oxidation reactions (HER/HOR) of platinum base employing N-methylimidazoles reorientate interfacial water against electric field as evidenced situ spectroscopic characterization We accordingly established a unified mechanism which HER/HOR acid proceeds via diffusion proton hydroxide, respectively, through interface...
A grand challenge in electrochemistry is to understand and promote electrochemical processes by exploring exploiting the interface. Herein, we promoted hydrogen evolution oxidation reactions (HER/HOR) of platinum base employing N-methylimidazoles reorientate interfacial water against electric field as evidenced situ spectroscopic characterization We accordingly established a unified mechanism which HER/HOR acid proceeds via diffusion proton hydroxide, respectively, through interface...
Recent progresses in hydroxide exchange membrane fuel cells (HEMFCs) have led to renewed interest the strong pH effect on hydrogen oxidation reaction (HOR) rate precious metals: two orders of magnitude decrease when is changed from 0 14. 1 Various theories been proposed explain this, ranging adsorbed cation effects, changes electric field strength, induced apparent binding energy. 2-4 One leading argument increase leads stronger and thus more rigid ordering water at electrode/electrolyte...
As the cornerstone for much of our electrochemical knowledge, inexplicable 2 orders magnitude decrease in hydrogen oxidation and evolution reactions (HOR/HER) moving from pH 1 to 14 on precious metals continues undermine understanding ability better design systems.1 Several theories have been proposed this anomalous change, electric field effects, influence cations, co-adsorption H OH, orientation interfacial water, driving innovations situ techniques, such as potential changes with Fourier...
The hydrogen evolution and oxidation reactions (HER/HOR) at the electrode-water control performance of water electrolyzers fuel cells, two important devices for deep decarbonization our economy (1). Platinum (Pt) catalyzes HER/HOR with exceptional activity stability across a wide pH range. However, its progressively decreases by about orders magnitude as increases from 0 to 13 (2, 3). lack understanding this dependence reflects fundamental knowledge gaps in electrochemistry has hindered...
The 2 orders of magnitude loss Platinum Group Metal (PGM) activity toward Hydrogen Oxidation and Reduction reactions (HOR/HER) has hindered implementation alkaline based electrolyzers fuel cells demonstrated a significant knowledge gap in our fundamental understanding electrochemical interfaces. 1 Beneath the seemingly simple reaction lies potentially convoluted mechanism, with various researchers assigning to shifts electrode potential zero free charge, changed binding energies adsorbates...
Oberflächenverstärkte Infrarotspektren zeigen, dass Grenzflächen-Kationen mit Elektrodenoberflächen interagieren, indem sie die Struktur des Wassers an der Grenzfläche verändern, und nicht ihre spezifische Adsorption. In ihrem Forschungsartikel auf S. 17882 demonstrieren Y. Yan, B. Xu et al., Modifizierung von Grenzflächenwasser den Schlüssel zur Verbesserung Kinetik Wasserstoffoxidation -entwicklung darstellen könnte.
The hydrogen evolution and oxidation reactions (HER/HOR) are the most fundamental in electrochemistry. They also electrochemical taking place practical devices such as H 2 fuel cells electrolyzers for conversion between electricity. Despite their importance, HER/HOR kinetics has remained not explicitly clear even platinum (Pt) electrode that been mostly studied. This is manifested by lack of consensus on why rate Pt about two orders magnitude slower alkaline (pH = 0) than acid 13), 1 a...
The puzzling pH dependence of HOR/HER leading to the approximately 2 orders magnitude loss in platinum group metal (PGM) activity base has hindered both practical design electrochemical devices as well fundamental understanding electrode/electrolyte interfaces. 1 Explanations for this effect have ranged from presence adsorbates specific alkaline conditions, shifts electrode potential zero free charge (pzfc) and subsequent strengthening interfacial electric field, 3 orientation water...