Catalytic Processes over Supported Nanoparticles: Simulations
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In heterogeneous catalysis, adsorption and reaction processes usually occur on supported metal nanoparticles. To study such processes experimentally, a variety of surface science techniques came into use in the last decades of the 20th century. Along with the appearance of high-precision techniques for surface characterization, considerable progress in the manufacturing of model catalysts with well-defined properties such as particle size, shape, and separation has been achieved. For example, modern electron beam lithography makes it possible to fabricate equisized and equidistant particles on the scale down to ∼ 10 nm. Despite this progress, the cognitive potential of the experimental studies in this field is still limited because the measurements are usually indirect and the information derived demands quantitative processing and interpretation. This can be done only with the use of mathematical models. Successful interpretation of the results requires constructing mathematical models providing accurate descriptions of the systems under consideration. Application of conventional mean-field models is often limited here because of the peculiarities of the reaction performance on the nanometer scale, including the inherent heterogeneity of metal crystallites as well as spontaneous and adsorbate-induced changes of the shape and degree of dispersion of supported catalysts. Under such circumstances, the use of stochastic simulations based, e.g., on the Monte Carlo (MC) technique, is almost inevitable. This entry focuses on theoretical studies (simulations) of catalytic reaction kinetics on active supported nanoparticles. Our goal is to describe the main achievements of the corresponding theoretical works.