A review of multiscale modeling of metal-catalyzed reactions: Mechanism development for complexity and emergent behavior
TL;DR: In this paper, the authors provide a perspective on multiscale modeling of catalytic reactions with emphasis on mechanism development and application to complex and emergent systems, and discuss the bond-order conservation method for thermochemistry and activation energy estimation.
About: This article is published in Chemical Engineering Science.The article was published on 2011-10-01 and is currently open access. It has received 313 citations till now. The article focuses on the topics: Multiscale modeling & Thermochemistry.
Summary (1 min read)
Jump to: [4.3 Elementary rate constant estimation from semi-empirical methods] – [11. Free energy calculations and accelerated molecular dynamics for catalysis in condensed phases] – [Surface Step:Total Sites Ratio] and [A perspective on multiscale modeling of mechanism development]
4.3 Elementary rate constant estimation from semi-empirical methods
- While semi-empirical methods are rarely as accurate as quantum mechanical approaches, they offer an inexpensive approach to estimating kinetic parameters.
- Essentially, this model offers a way to predict the activation energy of a reaction using the energy of reaction, from the correlation developed from similar reactions that belong to the same homologous series (these relationships have been used for free energies as well as enthalpies).
- This can be a valuable analysis for catalyst design by understanding trends of intermediate binding energy on different catalyst surfaces.
- In doing so, the refined parameters may not be unique (Prasad et al., 2009) but at least are physically relevant.
- As an example of a semi-empirical based microkinetic model addressing structure sensitivity, the CO oxidation reaction is considered (Wang et al., 2011, submitted).
11. Free energy calculations and accelerated molecular dynamics for catalysis in condensed phases
- The majority of first-principle studies in catalysis have considered reactions on metals in vacuo.
- While the aforementioned techniques have successfully been applied to enzymatic and liquid phase reactions, their extension to heterogeneous gas-solid and liquid-solid catalytic reactions is just emerging (Vlachos and Caratzoulas, 2010).
- This review paper described recent developments and a perspective in multiscale modeling with focus on reaction chemistry and mechanism, i.e., at phenomena spanning from the electronic up to and including the mesoscopic scale.
- Hierarchical multiscale modeling was discussed as an approach to coping with the complexity of realistic systems.
Surface Step:Total Sites Ratio
- Multiple scales (b) Ei = 41 kcal/mol (c) Ei = 23 kcal/mol (a) Ei = 54 kcal/mol Intrinsic heterogeneity in adsorbate distribution catalyst sites Many-body effects Multiple phases Catalyst dynamics reconstruction isomerization edge corner support (111) (100) Missing row reconstruction on (110) plane 71 a) b) Figure 4. Schematic of sample thermochemical property evolution with elementary reaction progression (a).
- (a) Flow of information in a multiscale kinetic Monte Carlo (KMC) framework: density functional theory (DFT) provides the vibrational frequencies of adsorbates and transition states.
A perspective on multiscale modeling of mechanism development
- Estimation of thermochemistry and kinetics via hierarchical multiscale methods Computation-driven catalyst design and discovery of materials with emergent behavior Uncertainty on catalyst design, particle effects, and structure sensitivity of reactions.
- Free energies in solution and solvent effects in catalytic reactions.
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TL;DR: The chiral stationary phase for high-performance liquid chromatography showed good chiral recognition ability and the chiral phase showed good Raman recognition ability, which is important for future generations of racemates.
Abstract: Supported Catalysts Weiting Yu,† Marc D. Porosoff,† and Jingguang G. Chen*,†,‡,§ †Catalysis Center for Energy Innovation, Department of Chemical and Bimolecular Engineering, University of Delaware, Newark, Delaware 19716, United States ‡Department of Chemical Engineering, Columbia University, New York, New York 10027, United States Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States
1,039 citations
358 citations
TL;DR: This review highlights the research using 3D printing and computational modeling as digital tools for the design and fabrication of reactors and structured catalysts in the field of catalytic technology and chemical engineering.
Abstract: Computer-aided fabrication technologies combined with simulation and data processing approaches are changing our way of manufacturing and designing functional objects. Also in the field of catalytic technology and chemical engineering the impact of additive manufacturing, also referred to as 3D printing, is steadily increasing thanks to a rapidly decreasing equipment threshold. Although still in an early stage, the rapid and seamless transition between digital data and physical objects enabled by these fabrication tools will benefit both research and manufacture of reactors and structured catalysts. Additive manufacturing closes the gap between theory and experiment, by enabling accurate fabrication of geometries optimized through computational fluid dynamics and the experimental evaluation of their properties. This review highlights the research using 3D printing and computational modeling as digital tools for the design and fabrication of reactors and structured catalysts. The goal of this contribution is to stimulate interactions at the crossroads of chemistry and materials science on the one hand and digital fabrication and computational modeling on the other.
307 citations
TL;DR: It is found that the charge state of the Au particle is negative in a reducing chemical environment whereas in the presence of oxidizing species coadsorbed to the oxide surface the cluster obtained a net positive charge.
Abstract: To probe metal particle/reducible oxide interactions density functional theory based ab initio molecular dynamics studies were performed on a prototypical metal cluster (Au20) supported on reducible oxides (rutile TiO2(110)) to implicitly account for finite temperature effects and the role of excess surface charge in the metal oxide. It is found that the charge state of the Au particle is negative in a reducing chemical environment whereas in the presence of oxidizing species coadsorbed to the oxide surface the cluster obtained a net positive charge. In the context of the well-known CO oxidation reaction, charge transfer facilitates the plasticization of Au20, which allows for a strong adsorbate induced surface reconstruction upon addition of CO leading to the formation of mobile Au–CO species on the surface. The charging/discharging of the cluster during the catalytic cycle of CO oxidation enhances and controls the amount of O2 adsorbed at oxide/cluster interface and strongly influences the energetics of...
280 citations
TL;DR: In this review, the detailed theory behind scaling relationships is discussed, and the existence of these relationships for catalytic materials ranging from pure metal to oxide surfaces, for numerous classes of molecules, and for a variety of catalytic surface structures is described.
Abstract: Scaling relationships are theoretical constructs that relate the binding energies of a wide variety of catalytic intermediates across a range of catalyst surfaces. Such relationships are ultimately derived from bond order conservation principles that were first introduced several decades ago. Through the growing power of computational surface science and catalysis, these concepts and their applications have recently begun to have a major impact in studies of catalytic reactivity and heterogeneous catalyst design. In this review, the detailed theory behind scaling relationships is discussed, and the existence of these relationships for catalytic materials ranging from pure metal to oxide surfaces, for numerous classes of molecules, and for a variety of catalytic surface structures is described. The use of the relationships to understand and elucidate reactivity trends across wide classes of catalytic surfaces and, in some cases, to predict optimal catalysts for certain chemical reactions, is explored. Finally, the observation that, in spite of the tremendous power of scaling relationships, their very existence places limits on the maximum rates that may be obtained for the catalyst classes in question is discussed, and promising strategies are explored to overcome these limitations to usher in a new era of theory-driven catalyst design.
278 citations
References
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Book•
01 Jan 2001
TL;DR: In this paper, the physics behind molecular simulation for materials science is explained, and the implementation of simulation methods is illustrated in pseudocodes and their practical use in the case studies used in the text.
Abstract: From the Publisher:
This book explains the physics behind the "recipes" of molecular simulation for materials science. Computer simulators are continuously confronted with questions concerning the choice of a particular technique for a given application. Since a wide variety of computational tools exists, the choice of technique requires a good understanding of the basic principles. More importantly, such understanding may greatly improve the efficiency of a simulation program. The implementation of simulation methods is illustrated in pseudocodes and their practical use in the case studies used in the text. Examples are included that highlight current applications, and the codes of the case studies are available on the World Wide Web. No prior knowledge of computer simulation is assumed.
6,901 citations
TL;DR: In this paper, the authors derived an expression for the total energy of a metal using the embedding energy from which they obtained several ground-state properties, such as the lattice constant, elastic constants, sublimation energy, and vacancy-formation energy.
Abstract: We develop the embedded-atom method [Phys. Rev. Lett. 50, 1285 (1983)], based on density-functional theory, as a new means of calculating ground-state properties of realistic metal systems. We derive an expression for the total energy of a metal using the embedding energy from which we obtain several ground-state properties, such as the lattice constant, elastic constants, sublimation energy, and vacancy-formation energy. We obtain the embedding energy and accompanying pair potentials semiempirically for Ni and Pd, and use these to treat several problems: surface energy and relaxation of the (100), (110), and (111) faces; properties of H in bulk metal (H migration, binding of H to vacancies, and lattice expansion in the hydride phase); binding site and adsorption energy of hydrogen on (100), (110), and (111) surfaces; and lastly, fracture of Ni and the effects of hydrogen on the fracture. We emphasize problems with hydrogen and with surfaces because none of these can be treated with pair potentials. The agreement with experiment, the applicability to practical problems, and the simplicity of the technique make it an effective tool for atomistic studies of defects in metals.
5,912 citations
"A review of multiscale modeling of ..." refers methods in this paper
...At the finer time-scale (order of several nanoseconds), molecular dynamics (MD) simulations were performed using the embedded atom method potential (Daw and Baskes, 1984; Foiles et al., 1986)....
[...]
Book•
01 Jan 2002
TL;DR: Understanding molecular simulation: From Algorithms to Applications explains the physics behind the "recipes" of molecular simulation for materials science as discussed by the authors, and provides a good understanding of the basic principles of simulation.
Abstract: Second and revised edition
Understanding Molecular Simulation: From Algorithms to Applications explains the physics behind the "recipes" of molecular simulation for materials science. Computer simulators are continuously confronted with questions concerning the choice of a particular technique for a given application. A wide variety of tools exist, so the choice of technique requires a good understanding of the basic principles. More importantly, such understanding may greatly improve the efficiency of a simulation program. The implementation of simulation methods is illustrated in pseudocodes and their practical use in the case studies used in the text.
Since the first edition only five years ago, the simulation world has changed significantly -- current techniques have matured and new ones have appeared. This new edition deals with these new developments; in particular, there are sections on:
· Transition path sampling and diffusive barrier crossing to simulaterare events
· Dissipative particle dynamic as a course-grained simulation technique
· Novel schemes to compute the long-ranged forces
· Hamiltonian and non-Hamiltonian dynamics in the context constant-temperature and constant-pressure molecular dynamics simulations
· Multiple-time step algorithms as an alternative for constraints
· Defects in solids
· The pruned-enriched Rosenbluth sampling, recoil-growth, and concerted rotations for complex molecules
· Parallel tempering for glassy Hamiltonians
Examples are included that highlight current applications and the codes of case studies are available on the World Wide Web. Several new examples have been added since the first edition to illustrate recent applications. Questions are included in this new edition. No prior knowledge of computer simulation is assumed.
5,859 citations
TL;DR: A powerful method for exploring the properties of the multidimensional free energy surfaces of complex many-body systems by means of coarse-grained non-Markovian dynamics in the space defined by a few collective coordinates is introduced.
Abstract: We introduce a powerful method for exploring the properties of the multidimensional free energy surfaces (FESs) of complex many-body systems by means of coarse-grained non-Markovian dynamics in the space defined by a few collective coordinates. A characteristic feature of these dynamics is the presence of a history-dependent potential term that, in time, fills the minima in the FES, allowing the efficient exploration and accurate determination of the FES as a function of the collective coordinates. We demonstrate the usefulness of this approach in the case of the dissociation of a NaCl molecule in water and in the study of the conformational changes of a dialanine in solution.
4,587 citations
"A review of multiscale modeling of ..." refers methods in this paper
...A more recent development in this front is Parrinello’s metadynamics method (Laio and Parrinello, 2002), a very promising approach that deserves special mention and for that we shall return to it shortly....
[...]
TL;DR: In this paper, an expression for the equilibrium free energy difference between two configurations of a system, in terms of an ensemble of finite-time measurements of the work performed in parametrically switching from one configuration to the other, is derived.
Abstract: An expression is derived for the equilibrium free energy difference between two configurations of a system, in terms of an ensemble of finite-time measurements of the work performed in parametrically switching from one configuration to the other. Two well-known identities emerge as limiting cases of this result.
4,496 citations
"A review of multiscale modeling of ..." refers methods in this paper
...A popular variant of it is called steered MD and is based on Jarzynksi’s equality, which allows the calculation of potentials of mean force from non-equilibrium trajectories (Jarzynski, 1997)....
[...]