A5101849688- Corrosion Behavior and Inhibition
- Hydrogen embrittlement and corrosion behaviors in metals
- Nuclear Materials and Properties
- Electrocatalysts for Energy Conversion
- High-Temperature Coating Behaviors
- Electrochemical Analysis and Applications
- Fusion materials and technologies
- Concrete Corrosion and Durability
- Catalytic Processes in Materials Science
- Radioactive element chemistry and processing
- Rare-earth and actinide compounds
- Machine Learning in Materials Science
- High Entropy Alloys Studies
- Advanced Chemical Physics Studies
- Advanced Materials Characterization Techniques
- Spectroscopy and Quantum Chemical Studies
- Nuclear reactor physics and engineering
- Fuel Cells and Related Materials
- Nuclear materials and radiation effects
- Thermodynamic and Structural Properties of Metals and Alloys
- High Temperature Alloys and Creep
- Magnesium Oxide Properties and Applications
- Graphite, nuclear technology, radiation studies
- Aluminum Alloy Microstructure Properties
- Electron and X-Ray Spectroscopy Techniques
DNV (Norway)
2015-2024
Colorado State University
2024
Quinnipiac University
2024
The Ohio State University
2014-2023
DNV (Netherlands)
2023
Los Alamos National Laboratory
2007-2018
Schlumberger (British Virgin Islands)
2016
Materials Science & Engineering
2006-2015
University of Akron
2013
Systems Analytics (United States)
2012
A method for calculating and subsequently tuning the electrochemical potential of a half cell using periodic plane-wave density functional theory homogenous counter-charge is presented evaluated by comparison to simulations which explicitly model countercharge plane ions. The involves establishment two reference potentials, one related free electron in vacuo, other ${\mathrm{H}}_{2}\mathrm{O}$ species far from electrode. surface can be specifically adjusted explicit introduction excess or...
Ab initio density functional theory is used to calculate the electrochemical phase diagram for oxidation and reduction of water over Pt(111) surface. Three different schemes proposed in literature are potential-dependent free energy hydrogen, water, hydroxyl, oxygen species adsorbed Despite foundations models their complexity, they can be directly related one another through a systematic Taylor series expansion Nernst equation. The simplest model, which includes potential only as shift...
The sluggish kinetics associated with the oxygen reduction reaction (ORR) at proton exchange membrane fuel cell cathode leads to high overpotentials and limits performance. Although significant progress has been made in first-principles modeling of ORR, complexity electrified aqueous/metal interface limited advances use theory elucidate influence electrode potential on mechanism kinetics. first step adsorbed molecular speculated be rate-determining ORR. Periodic density functional...
The structure of active sites in Fe-based nonprecious metal oxygen reduction reaction catalysts remains unknown, limiting the ability to follow a rational design paradigm for catalyst improvement. Previous studies indicate that N-coordinated Fe defects at graphene edges are most stable such sites. Density functional theory is used determination potential Clusters Fe–Nx found have N-coordination-dependent stability. Previously reported interedge structures be significantly less than in-edge...
Abstract We report calculated oxygen reduction reaction energy pathways on multi-metal-atom structures that have previously been shown to be thermodynamically favorable. predict such sites the ability spontaneously cleave O 2 bond and then will proceed over-bind intermediates. In particular, *OH bound state has lower than final H at positive potentials. Contrary traditional surface catalysts, this binding does not poison site but acts as a modifying ligand form in aqueous environments...
Abstract Structure, composition and surface properties dictate corrosion resistance in any given environment. The degrees of freedom alloy design are too numerous emerging materials such as high entropy alloys bulk metallic glasses for the use high-throughput methods or trial error. We review three domains knowledge that can be applied towards goal resistant (CRA) design: (a) aggregation gained through experience developing CRAs empirically, (b) data-driven approaches descriptive metrics...
Corrosion is an electrochemical phenomenon. It can occur via different modes of attack, each having its own mechanisms, and therefore there are multiple metrics for evaluating corrosion resistance. In resistant alloys (CRAs), the rate localized exceed that uniform by orders magnitude. Therefore, instead rate, more complex parameters required to capture salient features phenomena. Here, we collect a database with emphasis on related corrosion. The six sections include data various metal...
First-principles calculations based on the projector augmented-wave (PAW) technique have been applied to prediction of materials properties $\ensuremath{\alpha}$-uranium and its (001) surface. The results PAW are shown be comparable in accuracy full-potential reported elsewhere. In addition calculating lattice constants elastic moduli, vacancy formation energy $(1.95\phantom{\rule{0.3em}{0ex}}\mathrm{eV})$, surface relaxation ($\ensuremath{-}3.5%$ for ${\ensuremath{\delta}}_{12}$ $+1.2%$...
Despite the growing interest in Mg and its alloys, their use has been largely limited due to high reactivity aqueous environments. Improving understanding of basic principles corrosion represents first step explain and, eventually, improve behaviour alloys. Herein an original mechanistic surface kinetic DFT model that clarifies mechanism anomalous HE on anodically polarised is presented. In accordance with several experimental observations, this describes proceeding at regions dominated by...
Abstract Parabolic rate constants, k p , were collected from published reports and calculated corrosion product data (sample mass gain or thickness) tabulated for 75 alloys exposed to temperatures between ~800 2000 K (~500–1700 o C; 900–3000 F). Data environments including lab air, ambient supercritical carbon dioxide, water, steam. Materials studied include low- high-Cr ferritic austenitic steels, nickel superalloys, aluminide materials. A combination of Arrhenius analysis, simple linear...
Selected thermodynamic properties of a model nanoparticle were calculated using density-functional theory to deduce the corrosion metal nanoparticles. More specifically, atom surface cohesive energies nanoparticles in ideal and nonideal configurations compared perfect lattice flat (111) terraces corrugated (113) "bulk" copper. The overall equilibrium reaction for dissociation water, hydrogen, oxygen, hydroxyl on both low-index surfaces order understand establish their potential reactivity....
During the processing of low-activity radioactive waste to generate solid forms (e.g., glass), technetium-99 (Tc) is concern because its volatility. A variety materials are under consideration capture Tc from streams, including iron oxyhydroxide, goethite (α-FeOOH), which was experimentally shown sequester Tc(IV). This material could ultimately be incorporated into glass or alternative low-temperature form matrices. However, questions remain regarding incorporation mechanism for Tc(IV) in...
A surface kinetic model is developed using a proposed mechanism for the anodic and cathodic branches of hydrogen evolution observed over magnesium (i.e. negative difference effect). The key element to that requires removal adsorbed OH from surface. This step achieved in branch by reductive desorption form OH− surface, dissolution both along with Mg atom which it attached (thus combined alongside Mg2+). Steady state theory applied derive expressions rate as function potential....
The utility of density functional theory (DFT) for modeling in materials science and engineering with a focus on corrosion, is broadly introduced, along an introduction to the technique, its i...
Electrochemical processes occurring in aqueous solutions are critically dependent upon the interaction between metal electrode and solvent. In this work, density functional theory is used to calculate potentials for which molecular water its activation products (adsorbed hydrogen hydroxide) stable when contact with an immersed Ni(111) electrode. The adsorption geometries of dissociation also determined as functions potential. At zero kelvin, activates form a surface hydroxide overlayer at...