Monte Carlo Simulation of Adsorption Processes on Heterogeneous Crystal Surfaces

Monte Carlo Simulation of Adsorption Processes on Heterogeneous Crystal Surfaces

Author: Leila Rajabibonab

Publisher:

Published: 2017

Total Pages: 150

ISBN-13:

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The simulation of adsorption processes on a heterogeneous crystal surface is the main interest of this thesis. Two applications of this event have been developed with Kinetic Monte Carlo simulation. One is how to control the crystal growth by macromolecules and the other is how to measure the effective rate of interactions near a crystal surface. The first part of this thesis, considers the effective rate of catalytic conversion on a heterogeneous catalytic surface. We assume the crystal surface has two types of active site, one is neutral and the other one is highly active. We compared our result from simulation with the analytical method that is given by the homogenization theory. Our result revealed the importance of patterns of surface energies and the size of them on reaction rate. In the second project we consider the adsorption of a homopolymer chain on a crystal surface with two types of surface energies in order to limit the growth of one site and let the other sites grow more. We developed a new Kinetic Monte Carlo simulation method in this part, which was also applied to block copolymer chains that are more complex than a homo-polymer chain. Using this method four important phases of the polymer chains at high temperatures and also the free energies of the system across different patterns of active sites have been found. We tested different types of co-polymers to find the most differentiative block copolymer for controlling the crystal growth.


Modeling and Simulation of Heterogeneous Catalytic Reactions

Modeling and Simulation of Heterogeneous Catalytic Reactions

Author: Olaf Deutschmann

Publisher: John Wiley & Sons

Published: 2013-09-18

Total Pages: 364

ISBN-13: 3527639888

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The Nobel Prize in Chemistry 2007 awarded to Gerhard Ertl for his groundbreaking studies in surface chemistry highlighted the importance of heterogeneous catalysis not only for modern chemical industry but also for environmental protection. Heterogeneous catalysis is seen as one of the key technologies which could solve the challenges associated with the increasing diversification of raw materials and energy sources. It is the decisive step in most chemical industry processes, a major method of reducing pollutant emissions from mobile sources and is present in fuel cells to produce electricity. The increasing power of computers over the last decades has led to modeling and numerical simulation becoming valuable tools in heterogeneous catalysis. This book covers many aspects, from the state-of-the-art in modeling and simulations of heterogeneous catalytic reactions on a molecular level to heterogeneous catalytic reactions from an engineering perspective. This first book on the topic conveys expert knowledge from surface science to both chemists and engineers interested in heterogeneous catalysis. The well-known and international authors comprehensively present many aspects of the wide bridge between surface science and catalytic technologies, including DFT calculations, reaction dynamics on surfaces, Monte Carlo simulations, heterogeneous reaction rates, reactions in porous media, electro-catalytic reactions, technical reactors, and perspectives of chemical and automobile industry on modeling heterogeneous catalysis. The result is a one-stop reference for theoretical and physical chemists, catalysis researchers, materials scientists, chemical engineers, and chemists in industry who would like to broaden their horizon and get a substantial overview on the different aspects of modeling and simulation of heterogeneous catalytic reactions.


Monte Carlo Simulations of Temperature-programmed and Isothermal Desorption from Single-crystal Surfaces

Monte Carlo Simulations of Temperature-programmed and Isothermal Desorption from Single-crystal Surfaces

Author:

Publisher:

Published: 1990

Total Pages: 316

ISBN-13:

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The kinetics of temperature-programmed and isothermal desorption have been simulated with a Monte Carlo model. Included in the model are the elementary steps of adsorption, surface diffusion, and desorption. Interactions between adsorbates and the metal as well as interactions between the adsorbates are taken into account with the Bond-Order-Conservation-Morse-Potential method. The shape, number, and location of the TPD peaks predicted by the simulations is shown to be sensitive to the binding energy, coverage, and coordination of the adsorbates. In addition, the occurrence of lateral interactions between adsorbates is seen to strongly effect the distribution of adsorbates is seen to strongly effect the distribution of adsorbates on the surface. Temperature-programmed desorption spectra of a single type of adsorbate have been simulated for the following adsorbate-metal systems: CO on Pd(100); H2 on Mo(100); and H2 on Ni(111). The model predictions are in good agreement with experimental observation. TPD spectra have also been simulated for two species coadsorbed on a surface; the model predictions are in qualitative agreement with the experimental results for H2 coadsorbed with strongly bound atomic species on Mo(100) and Fe(100) surfaces as well as for CO and H2 coadsorbed on Ni(100) and Rh(100) surfaces. Finally, the desorption kinetics of CO from Pd(100) and Ni(100) in the presence of gas-phase CO have been examined. The effect of pressure is seen to lead to an increase in the rate of desorption relative to the rate observed in the absence of gas-phase CO. This increase arises as a consequence of higher coverages and therefore stronger lateral interactions between the adsorbed CO molecules.


Modeling and Simulation of Heterogeneous Catalytic Processes

Modeling and Simulation of Heterogeneous Catalytic Processes

Author:

Publisher: Academic Press

Published: 2014-09-22

Total Pages: 312

ISBN-13: 012800455X

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Heterogeneous catalysis and mathematical modeling are essential components of the continuing search for better utilization of raw materials and energy, with reduced impact on the environment. Numerical modeling of chemical systems has progressed rapidly due to increases in computer power, and is used extensively for analysis, design and development of catalytic reactors and processes. This book presents reviews of the state-of-the-art in modeling of heterogeneous catalytic reactors and processes. Reviews by leading authorities in the respective areas Up-to-date reviews of latest techniques in modeling of catalytic processes Mix of US and European authors, as well as academic/industrial/research institute perspectives Connections between computation and experimental methods in some of the chapters


Monte Carlo Diffusion Studies

Monte Carlo Diffusion Studies

Author: D.J. Fisher

Publisher: Trans Tech Publications Ltd

Published: 2015-02-13

Total Pages: 266

ISBN-13: 3038266507

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The Monte Carlo method, largely the brainchild of Stanislaw Ulam and first implemented by John von Neumann, depends upon the use of digital computers and is therefore very much a product of post-WW2 technological developments; even though one could argue that the Buffon’s Needle estimate was an ancestor of the technique. The probabilistic nature of the method makes it a good choice for modeling those physical phenomena which involve similarly random motions at the atomic scale; a particularly good example being that of mass diffusion. The present volume comprises a compilation of selected Monte Carlo studies of diffusion in borides, carbides, diamond, graphene, graphite, hydrides, ice, metals, oxides, semiconductors, sulfides, zeolites and other materials. General aspects of diffusion are also covered. The 516 entries cover the period from 1966 to 2014.


Computational Methods in Surface and Colloid Science

Computational Methods in Surface and Colloid Science

Author: Malgorzata Borowko

Publisher: CRC Press

Published: 2019-04-23

Total Pages: 958

ISBN-13: 1420030035

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This volume presents computer simulation methods and mathematical modelling of physical processes used in surface science research. It offers in-depth analysis of advanced theoretical approaches to behaviours of fluids in contact with porous, semiporous and nonporous solid surfaces. The book also explores interfacial systems for a wide variety of p