A5049777382- Electrocatalysts for Energy Conversion
- Machine Learning in Materials Science
- CO2 Reduction Techniques and Catalysts
- Catalytic Processes in Materials Science
- Electrochemical Analysis and Applications
- Advanced battery technologies research
- Ionic liquids properties and applications
- Fuel Cells and Related Materials
- Molecular Junctions and Nanostructures
- X-ray Diffraction in Crystallography
- Subcritical and Supercritical Water Processes
- Advanced Chemical Physics Studies
- Crystallization and Solubility Studies
- Catalysts for Methane Reforming
- Catalysis and Oxidation Reactions
- Catalysis and Hydrodesulfurization Studies
- Icing and De-icing Technologies
- Ammonia Synthesis and Nitrogen Reduction
- nanoparticles nucleation surface interactions
- COVID-19 epidemiological studies
- Mathematical and Theoretical Epidemiology and Ecology Models
- Spectroscopy and Quantum Chemical Studies
- Heat transfer and supercritical fluids
- Advancements in Battery Materials
- 2D Materials and Applications
John Brown University
2013-2025
Brown University
2016-2025
Technical University of Denmark
2010-2024
Providence College
2014-2021
Interface (United States)
2011-2016
Stanford University
2011-2016
Stanford Medicine
2016
SLAC National Accelerator Laboratory
2013
Menlo School
2013
Massachusetts Institute of Technology
2007-2011
The atomic simulation environment (ASE) is a software package written in the Python programming language with aim of setting up, steering, and analyzing atomistic simulations. In ASE, tasks are fully scripted Python. powerful syntax combined NumPy array library make it possible to perform very complex tasks. For example, sequence calculations may be performed use simple 'for-loop' construction. Calculations energy, forces, stresses other quantities through interfaces many external electronic...
Density functional theory calculations explain copper's unique ability to convert CO2 into hydrocarbons, which may open up (photo-)electrochemical routes fuels.
The electrochemical reduction of CO2 into hydrocarbons and alcohols would allow renewable energy sources to be converted fuels chemicals. However, no electrode catalysts have been developed that can perform this transformation with a low overpotential at reasonable current densities. In work, we compare trends in binding energies for the intermediates present an activity “volcano” based on analysis. This analysis describes experimentally observed variations transition-metal catalysts,...
We report selective electrocatalytic reduction of carbon dioxide to monoxide on gold nanoparticles (NPs) in 0.5 M KHCO3 at 25 °C. Among monodisperse 4, 6, 8, and 10 nm NPs tested, the 8 Au show maximum Faradaic efficiency (FE) (up 90% -0.67 V vs reversible hydrogen electrode, RHE). Density functional theory calculations suggest that more edge sites (active for CO evolution) than corner competitive H2 evolution reaction) NP surface facilitates stabilization intermediates, such as COOH*,...
In this communication, we show that ultrathin Au nanowires (NWs) with dominant edge sites on their surface are active and selective for electrochemical reduction of CO2 to CO. We first develop a facile seed-mediated growth method synthesize these (2 nm wide) NWs in high yield (95%) by reducing HAuCl4 the presence 2 nanoparticles (NPs). These catalyze CO aqueous 0.5 M KHCO3 at an onset potential −0.2 V (vs reversible hydrogen electrode). At −0.35 V, Faradaic efficiency (FE) reaches 94% (mass...
We develop a model based on density functional theory calculations to describe trends in catalytic activity for CO2 electroreduction CO terms of the adsorption energy reaction intermediates, and COOH. The is applied metal surfaces as well active site CODH enzymes shows that strong scaling between adsorbed COOH responsible persistent overpotential. enzyme not subject these relations optimizes relative binding energies adsorbates, allowing an essentially reversible process with low
This communication examines the effect of surface morphology polycrystalline copper on electroreduction CO(2). We find that a nanoparticle covered electrode shows better selectivity towards hydrocarbons compared with two other studied surfaces, an electropolished and argon sputtered electrode. Density functional theory calculations provide insight into effect.
The well-known hydrogen evolution reaction (HER) volcano plot describes the relationship between H binding energy and corresponding catalytic activity, which depends on species of metal. Under CO2/CO reduction conditions or in cases where CO impurities enter electrodes, catalyst may exist under a high coverage coadsorbed CO. We present DFT calculations that suggest during will weaken strength surface. For metals right-hand side (too weak binding) this should lead to suppression HER, as has...
Metal carbide catalysts are alternative nonprecious electrode materials for electrochemical energy conversion devices, such as H2 fuel cells or electrolyzers. In this article, we report the experimental exchange current densities hydrogen evolution reaction (HER) on eight mono- and bimetallic electrocatalysts correlate to binding energies that have calculated via electronic structure computations. We find these activities higher than those of their parent metals intermediate between...
Abstract We present a first‐principles theoretical study of carbon–carbon coupling in CO 2 electroreduction on the copper 1 surface. Using DFT, we have determined kinetic barriers to formation CC bond between adsorbates derived from CO. The results our nudged elastic band calculations demonstrate that decrease significantly with degree hydrogenation reacting adsorbates. also show this trend is not affected by electrical fields at solid‐electrolyte interface during electrocatalysis. Our...
The catalytic activities of sulfur sites in amorphous MoSx for the electrochemical hydrogen evolution reaction (HER) was investigated aqueous 0.5 M H2SO4 electrolyte. Using X-ray photoelectron spectroscopy and linear sweep voltammetry, we found turnover frequency H2 production to increase linearly with percentage S atoms higher electron binding energies. These could be apical S2– and/or bridging S22–. To distinguish performances these two types atoms, turn quantum chemical simulations using...
Amorphous molybdenum sulfide (MoSx) is currently being developed as an economically viable and efficient catalyst for the electrochemical hydrogen evolution reaction (HER). An important yet unsolved problem in this ongoing effort identification of its catalytically active sites proton reduction. In work, cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), Raman were used to investigate structural MoSx films during HER 1 M HClO4 electrolyte. Transformation anodically deposited (x...
The activity of many heterogeneous catalysts is limited by strong correlations between activation energies and adsorption reaction intermediates. Although the thermodynamically favourable at ambient temperature pressure, catalytic synthesis ammonia (NH3), a fertilizer chemical fuel, from N2 H2 requires some most extreme conditions industry. We demonstrate how can be produced pressure air, water, concentrated sunlight as renewable source process heat via nitrogen reduction with looped metal...
The simulation of electrochemical reaction dynamics from first principles remains challenging, since over the course an elementary step, electron is either consumed or produced by electrode. For example, hydrogen evolution begins with a simple proton discharge to metal surface, but conventional electronic structure methods, simulated potential, which manifested as metal's workfunction, varies in new metal–hydrogen bond. Here, we present approach allow direct control potential via charging...
Platinum is a nearly perfect catalyst for the hydrogen evolution reaction, and its high activity has conventionally been explained by close-to-thermoneutral binding energy (G~0). However, many candidate non-precious metal catalysts bind with similar strengths, but exhibit orders-of-magnitude lower this reaction. In study, we employ electronic structure methods that allow fully potential-dependent reaction barriers to be calculated, in order develop complete working picture of on platinum....
We review the GPAW open-source Python package for electronic structure calculations. is based on projector-augmented wave method and can solve self-consistent density functional theory (DFT) equations using three different wave-function representations, namely real-space grids, plane waves, numerical atomic orbitals. The representations are complementary mutually independent be connected by transformations via grid. This multi-basis feature renders highly versatile unique among similar...
Kinetic and mechanistic evidence is presented of the occurrence a Maillard-type reaction under conditions interest to hydrothermal biomass processing. Glucose−glycine mixtures were reacted at 250 °C 10 MPa in an excess water; both glucose glycine found strongly influence destruction kinetics other species result quantitative qualitative changes, such as strong absorbance 420 nm production dark brown appearance nutty odor, which are characteristic Maillard reaction. The presence always...
Machine-learning regression can precisely emulate the potential energy and forces of more expensive electronic-structure calculations, but to make useful predictions an assessment must be made prediction's credibility.
In atomistic simulations, the location of saddle point on potential-energy surface (PES) gives important information transitions between local minima, for example, via transition-state theory. However, search points often involves hundreds or thousands ab initio force calls, which are typically all done at full accuracy. This results in vast majority computational effort being spent calculating electronic structure states not to researcher, and very little time performing calculation state...
We use density functional theory to study the reduction of CO<sub>2</sub>and CO hydrocarbons through a formyl pathway on (111) and (211) facets L1<sub>2</sub>alloys with an A<sub>3</sub>B composition.