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A precise control of the size, density and distribution of metal nanoparticles dispersed on functional oxide supports is critical for promoting catalytic activity and stability in renewable energy and catalysis devices. Here, we measure the growth kinetics of individual Co particles ex-solved on SrTi0.75Co0.25O3-δ polycrystalline thin films under a high vacuum, and at various temperatures and grain sizes using in situ transmission electron microscopy. The ex-solution preferentially occurs at grain boundaries and corners which appear essential for controlling particle density and distribution, and enabling low temperature ex-solution. The particle reaches a saturated size after a few minutes, and the size depends on temperature. Quantitative measurements with a kinetic model determine the rate limiting step, vacancy formation enthalpy, ex-solution enthalpy and activation energy for particle growth. The ex-solved particles are tightly socketed, preventing interactions among them over 800 °C. Furthermore, we obtain the first direct clarification of the active reaction site for CO oxidation ‒ the Co-oxide interface, agreeing well with DFT calculations.
This article was published in the following journal.
Name: Journal of the American Chemical Society
The time evolution of a system of coagulating particles under the product kernel and arbitrary initial conditions is studied. Using the improved Marcus-Lushnikov approach, the master equation is solve...
Although ambient particulate matter or particles have been found to be associated with morbidity and mortality all over the world, specific health effects of particles from different sources need furt...
The standard model for diffusion and surface kinetics driven growth of a single spherical particle in solution is applied incorrectly throughout the literature. This leads to inaccurate values for par...
Functionalizing transparent conducting oxides (TCOs) is an intriguing approach to expand the tunability and operation of optoelectronic devices. For example, forming nanoparticles that act as qu...
The combined effects of pH, dissolved organic carbon (DOC) and Ca/Mg on the dissolution and aggregation kinetics of zero valent copper engineered nanoparticles (Cu ENPs) were investigated. The dissolu...
Women were given a vitamin A tracer, and blood was sampled to determine individual and group vitamin A kinetics. Data were subsequently modeled using compartmental analysis to determine ef...
The main purpose of this study is to update the pulmonary retention values of non-fibrous mineral particles in the general population. This study will provide reference values for the int...
This will be a prospective study conducted on women with a suspected/confirmed diagnosis of placental abruption. Maternal blood samples will be taken at various points during the peripartu...
The primary goal of the study is to see if the PET/CT will be able to determine the precise location of the Y-90 particles within the liver and within the tumors. We hope to use this infor...
The purpose of this study is to test if PET scans using 89Zr-DFO-cRGDY-PEG-Cy5-C' dot particles, can be used to take pictures of brain tumors. The investigators want to understand how the ...
Individual components of atoms, usually subatomic; subnuclear particles are usually detected only when the atomic nucleus decays and then only transiently, as most of them are unstable, often yielding pure energy without substance, i.e., radiation.
The interactions of particles responsible for their scattering and transformations (decays and reactions). Because of interactions, an isolated particle may decay into other particles. Two particles passing near each other may transform, perhaps into the same particles but with changed momenta (elastic scattering) or into other particles (inelastic scattering). Interactions fall into three groups: strong, electromagnetic, and weak. (From McGraw-Hill Encyclopedia of Science & Technology, 7th ed)
Gradual increase in the number, the size, and the complexity of cells of an individual. Growth generally results in increase in ORGAN WEIGHT; BODY WEIGHT; and BODY HEIGHT.
Computer programs based on knowledge developed from consultation with experts on a problem, and the processing and/or formalizing of this knowledge using these programs in such a manner that the problems may be solved.
Synthesized magnetic particles under 100 nanometers possessing many biomedical applications including DRUG DELIVERY SYSTEMS and CONTRAST AGENTS. The particles are usually coated with a variety of polymeric compounds.