A5063674208- Catalytic Processes in Materials Science
- Catalysis and Hydrodesulfurization Studies
- Catalysis and Oxidation Reactions
- Electrocatalysts for Energy Conversion
- Catalysis for Biomass Conversion
- Electronic and Structural Properties of Oxides
- Advancements in Solid Oxide Fuel Cells
- Nanomaterials for catalytic reactions
- Machine Learning in Materials Science
- Catalysts for Methane Reforming
- Magnetic and transport properties of perovskites and related materials
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Ammonia Synthesis and Nitrogen Reduction
- Zeolite Catalysis and Synthesis
- Computational Drug Discovery Methods
- Asymmetric Hydrogenation and Catalysis
- Metal-Organic Frameworks: Synthesis and Applications
- Theoretical and Computational Physics
- Molecular Junctions and Nanostructures
- Protein Structure and Dynamics
- Carbon dioxide utilization in catalysis
- Lignin and Wood Chemistry
- Copper-based nanomaterials and applications
- Advanced Photocatalysis Techniques
University of South Carolina
2015-2024
Software (Spain)
2017
University of Minnesota
2006-2008
Nicolaus Copernicus University
2008
Institute of Physics
2008
University of Colorado Denver
2007
Universität Hamburg
2002-2007
University of California, Berkeley
2005-2007
Hamburg University of Technology
2001-2007
Université de Lorraine
2003
A combination of interpolation methods and local saddle-point search algorithms is probably the most efficient way finding transition states in chemical reactions. Interpolation such as growing-string method nudged-elastic band are able to find an approximation minimum-energy pathway thereby provide a good initial guess for state imaginary mode connecting both reactant product states. Since employ usually just small number configurations converge slowly close pathway, partitioned rational...
Our civilization relies on synthetic polymers for all aspects of modern life; yet, inefficient recycling and extremely slow environmental degradation plastics are causing increasing concern about their widespread use. After a single use, many these materials currently treated as waste, underutilizing inherent chemical energy value. In this study, energy-rich polyethylene (PE) macromolecules catalytically transformed into value-added products by hydrogenolysis using well-dispersed Pt...
Interpolation methods such as the nudged elastic band and string are widely used for calculating minimum energy pathways transition states chemical reactions. Both require an initial guess reaction pathway. A poorly chosen can cause slow convergence, convergence to incorrect pathway, or even failed electronic structure force calculations along guessed This paper presents a growing method that find without requirement of The begins two fragments, one associated with reactants other products....
Reaction pathways and kinetics governing the Ru-catalyzed hydrogenation of levulinic acid (LA) in aqueous phase to form γ-valerolactone (GVL) were considered a packed bed reactor. GVL can be produced by two distinct pathways; however, over Ru/C at temperatures below 423 K, it forms exclusively via intramolecular esterification 4-hydroxypentanoic (HPA). Over Ru/C, reasonable rates LA HPA observed near-ambient (e.g., 0.08 s–1 323 K), but selectivities are poor (<5%) under these conditions....
The development of porous well-defined hybrid materials (e.g., metal–organic frameworks or MOFs) will add a new dimension to wide number applications ranging from supercapacitors and electrodes “smart” membranes thermoelectrics. From this perspective, the understanding tailoring electronic properties MOFs are key fundamental challenges that could unlock full potential these materials. In work, we focused on insights responsible for three distinct classes bimetallic systems, Mx–yM′y-MOFs,...
Chemical kinetic modeling in heterogeneous catalysis is advancing its ability to provide qualitatively or even quantitatively accurate prediction of real-world behavior because new advances the physical and chemical representations catalytic systems, estimation relevant parameters, capabilities modeling. This Perspective describes current trends future areas advancement modeling, simulation, parameter estimation: ranging from elementary step calculations multiscale role advanced statistical...
A catalytic architecture, comprising a mesoporous silica shell surrounding platinum nanoparticles (NPs) supported on solid sphere (mSiO2/Pt-X/SiO2; X is the mean NP diameter), catalyzes hydrogenolysis of melt-phase polyethylene (PE) into narrow C23-centered distribution hydrocarbons in high yield using very low Pt loadings (∼10–5 g Pt/g PE). During catalysis, polymer chain enters pore and contacts where C–C bond cleavage occurs then smaller fragment exits pore. mSiO2/Pt/SiO2 resists...
Abstract Carbon–carbon bond cleavage reactions, adapted to deconstruct aliphatic hydrocarbon polymers and recover the intrinsic energy carbon value in plastic waste, have typically been catalysed by metal nanoparticles or air-sensitive organometallics. Metal oxides that serve as supports for these catalysts are considered be inert. Here we show Earth-abundant, non-reducible zirconia catalyses hydrogenolysis of polyolefins with activity rivalling precious nanoparticles. To harness this...
In many applications of multilevel/multiscale methods, an active zone must be modeled by a high-level electronic structure method, while larger environmental can safely lower-level molecular mechanics, or analytic potential energy function. some cases though, the redefined as function simulation time. Examples include reactive moiety diffusing through liquid solid, dislocation propagating material, solvent molecules in second coordination sphere (which is environmental) exchanging with first...
The reaction mechanism for nitrous oxide decomposition has been studied on hydrated and dehydrated mononuclear iron sites in Fe−ZSM-5 using density functional theory. In total, 46 different surface species with spin states (spin multiplicity MS = 4 or 6) 63 elementary reactions were considered. Heats of adsorption, activation barriers, rates, minimum energy pathways determined. approximate transition calculated the "growing string method" a modified "dimer method". Spin crossing (e.g., O2...
Lignin in lignocellulosic biomass is the only renewable source for aromatic compounds, and effective valorization of lignin remains a significant challenge conversion processes. We have performed density functional theory calculations experiments to investigate cleavage mechanism C–O ether bond model compound 2-phenoxy-1-phenylethanol with β-O-4 linkage over Pd(111) catalyst surface model. propose favorable reaction pathway proceed as follows: dilignol reactant gets dehydrogenated first on...
ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTLiquid-Phase Modeling in Heterogeneous CatalysisMohammad Saleheen and Andreas Heyden*View Author Information Department of Chemical Engineering, University South Carolina, 301 Main Street, Columbia, Carolina 29208, United States*E-mail: [email protected]Cite this: ACS Catal. 2018, 8, 3, 2188–2194Publication Date (Web):January 29, 2018Publication History Received19 December 2017Published online7 February 2018Published inissue 2 March...
The reaction mechanism of the mild hydrogenation guaiacol over Pt(111) has been investigated by density functional theory calculations and microkinetic modeling. Our model suggests that at 573 K, catechol is preferred product any deoxygenation to, for example, phenol or benzene least 4 orders magnitude slower than production catechol. Slow can occur decarbonylation possibly phenyl ring followed C–OH bond cleavage. Direct −OH removal without activation found to be 5 slower. Overall, this...
We have developed an integrated approach that combines synthesis, X-ray photoelectron spectroscopy (XPS) studies, and theoretical calculations for the investigation of active unsaturated metal sites (UMS) in copper-based metal–organic frameworks (MOFs). Specifically, extensive reduction Cu+2 to Cu+1 at MOF nodes was achieved. Introduction mixed valence copper resulted significant changes band structure increased density states near Fermi edge, thereby altering electronic properties...
Atomically dispersed supported metal catalysts offer unique opportunities for designing highly selective and maximizing the utility of precious metals that have potential applications in a wide variety industrial chemical reactions. Although substantial advances understanding origin activity such been made few reactions, reaction mechanisms nature active site—small clusters versus single atoms—are still debated. Using combination density functional theory microkinetic modeling, we confirm...
Computational catalyst screening has the potential to significantly accelerate heterogeneous discovery. Typically, this involves developing microkinetic reactor models that are based on parameters obtained from density functional theory and transition-state theory. To reduce large computational cost involved in computing various adsorption energies of all possible surface states a number models, linear scaling relations for intermediates transition have been developed only depend few,...
We derive a Hamiltonian and present simulation protocol for mixed-resolution systems that allows change in resolution of selected groups atoms during molecular dynamics simulation. The uses low-resolution force field the part system distant from an active site (for efficiency) atomistic its direct environment accuracy). A microcanonical conserves energy angular linear momentum. method is also applicable to simulations other ensembles.