A5005598291- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Electrochemical Analysis and Applications
- Catalytic Processes in Materials Science
- Advanced battery technologies research
- Molecular Junctions and Nanostructures
- Advancements in Battery Materials
- Machine Learning in Materials Science
- Advanced Chemical Physics Studies
- Advanced Materials Characterization Techniques
- Conducting polymers and applications
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Semiconductor materials and devices
- Electron and X-Ray Spectroscopy Techniques
- CO2 Reduction Techniques and Catalysts
- Advanced Memory and Neural Computing
- Advancements in Solid Oxide Fuel Cells
- Catalysis and Oxidation Reactions
- Surface and Thin Film Phenomena
- Catalysis and Hydrodesulfurization Studies
- Analytical Chemistry and Sensors
- nanoparticles nucleation surface interactions
- Electronic and Structural Properties of Oxides
- Advanced Electron Microscopy Techniques and Applications
University of California, Irvine
2021-2025
Argonne National Laboratory
2014-2023
Samueli Institute
2022
Zdravstveni centar
2016
University of Illinois Chicago
2015
Brown University
2013
Johns Hopkins University
2013
Material Sciences (United States)
2010
National Institute of Chemistry
2007-2010
University of Ljubljana
2010
The slow rate of the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cell (PEMFC) is main limitation for automotive applications. We demonstrated that Pt3Ni(111) surface 10-fold more active ORR than corresponding Pt(111) and 90-fold current state-of-the-art Pt/C catalysts PEMFC. has an unusual electronic structure (d-band center position) arrangement atoms near-surface region. Under operating conditions relevant to cells, its layer exhibits a highly structured...
Combining two different types of catalysts accelerated the hydrogen-generation step in water electrolysis.
Giving Electrocatalysts an Edge Platinum (Pt) is excellent catalyst for the oxygen-reduction reaction (ORR) in fuel cells and electrolyzers, but it too expensive scarce widespread deployment, even when dispersed as Pt nanoparticles on carbon electrode supports (Pt/C). Alternatively, Chen et al. (p. 1339 , published online 27 February; see Perspective by Greer ) made highly active ORR catalysts dissolving away interior of rhombic dodecahedral PtNi 3 nanocrystals to leave Pt-rich Ni edges....
Going platinum: The theoretical description of electrocatalytic phenomena is extremely challenging. A simple, density functional theory based model has been developed that able to give a semiquantitative the reaction kinetics for oxygen reduction on several platinum binary alloys, Pt3M (see graph).
The surface properties of PtM (M = Co, Ni, Fe) polycrystalline alloys are studied by utilizing Auger electron spectroscopy, low energy ion scattering and ultraviolet photoemission spectroscopy. For each alloy initial characterization was done in an ultrahigh vacuum (UHV) system, depending on preparation procedure it possible to form surfaces with two different compositions. Due segregation thermodynamics, annealed the outermost Pt-skin layer, which consists only platinum atoms, while...
We describe a comparative study of the oxygen reduction reaction on two carbon-supported Pt-based alloy catalysts in aqueous acidic electrolyte at low temperature. Both alloys have bulk compositions 50 and 75 at. % Pt, with alloying elements being Ni Co. Comparison is made to pure Pt catalyst same carbon support, Vulcan XC-72, having metal loading (20 wt %) nominally particle size (4 ± 2 nm). High-resolution electron microscopy was used determine shape particles as well distribution all...
The oxygen reduction reaction (ORR) has been studied on polycrystalline Pt3Ni and Pt3Co alloys in acid electrolytes using the rotating ring disk electrode (RRDE) method. Preparation characterization of alloy surfaces were performed ultrahigh vacuum (UHV). Clearly defined surface composition was determined via low-energy ion-scattering (LEIS) spectroscopy. Polycrystalline bulk prepared UHV having two different compositions: one with 75% Pt other 100% Pt. latter we call a "Pt-skin" structure...
Active in alkaline environment: The activity of nickel, silver, and copper catalysts for the electrochemical transformation water to molecular hydrogen solutions was enhanced by modification metal surfaces Ni(OH)(2) (see picture; I = current density η overpotential). evolution reaction rate on a Ni electrode modified nanoclusters is about four times higher than bare surface.
In the present study, we used a surface-science approach to establish functional link between activity and stability of monometallic oxides during OER in acidic media. We found that most active (Au ≪ Pt < Ir Ru Os) are, fact, least stable ≫ > materials. suggest relationships are controlled by both nobility as well density surface defects. This functionality is governed nature metal cations potential transformation cation with valence state n = +4 unstable +4. A practical consequence such...
The particle size effect on the formation of OH adlayer, CO bulk oxidation, and oxygen reduction reaction (ORR) have been studied Pt nanoparticles in perchloric acid electrolyte. From measurements displacement charge at controlled potential, corresponding surface density versus potential curves yielded potentials total zero (pztc), which shifts approximately 35 mV negative by decreasing from 30 nm down to 1 nm. As a consequence, energy adsorption is more enhanced, that is, same coverage with...
Advancement in heterogeneous catalysis relies on the capability of altering material structures at nanoscale, and that is particularly important for development highly active electrocatalysts with uncompromised durability. Here, we report design synthesis a Pt-bimetallic catalyst multilayered Pt-skin surface, which shows superior electrocatalytic performance oxygen reduction reaction (ORR). This novel structure was first established thin film extended surfaces tailored composition profiles...
Platin im Blick: Die theoretische Beschreibung elektrokatalytischer Phänomene ist eine große Herausforderung. Ein einfaches Modell auf der Grundlage Dichtefunktionaltheorie liefert nun halbquantitative Kinetik elektrokatalytischen Sauerstoffreduktion an einer Reihe binärer Platinlegierungen (Pt3M, siehe Diagramm).
Using high-resolution transmission electron microscopy (TEM), infrared reflection-absorption spectroscopy (IRAS), and electrochemical (EC) measurements, platinum nanoparticles ranging in size from 1 to 30 nm are characterized their catalytic activity for CO electrooxidation is evaluated. TEM analysis reveals that Pt crystallites not perfect cubooctahedrons, large particles have "rougher" surfaces than small particles, which some fairly smooth (111) facets. The importance of "defect" sites...
Colloidal nanoparticles prepared by solution synthesis with robust control over particle size, shape, composition, and structure have shown great potential for catalytic applications. However, such colloidal are usually capped organic ligands (as surfactants) cannot be directly used as catalyst. We studied the effect of surfactant removal on electrocatalytic performance Pt made synthesis. Various methods were applied to remove oleylamine surfactant, which included thermal annealing, acetic...