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Catalyst Catalysis

Catalyst Catalysis. catalysis. Mechanisms of catalytic reactions, elementary reactions, surface reactivity, adsorption of reactants on the solid surfaces, synthesis and structure of solid materials, enzymes, or organometallic complexes.

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Catalyst Catalysis

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  1. Catalyst Catalysis

  2. catalysis • Mechanisms of catalytic reactions, elementary reactions, surface reactivity, adsorption of reactants on the solid surfaces, synthesis and structure of solid materials, enzymes, or organometallic complexes. • Heterogeneous catalysts in the form of porous solids to homogeneous catalysts dissolved in the liquid reaction mixture to biological catalysts in the form of enzymes.

  3. fields of chemistry, physics and biology to work together to achive the goals set by the mankind. • Knowledge of inorganic, organometallic, organic chemistry, materials and surface science, solid state physics, spectroscopy, reaction engineering, and enzymology

  4. A comparison between homogeneous and heterogeneous catalysts Homogeneous Heterogeneous • Activity high variable • Selectivity high variable • Conditions of reaction mild harsh • Life time of catalyst variable long • Sensitivity to deactivation low high • Problems due to diffusion none difficult to solve • Recycling of catalyst usually difficult can easily be done • Steric and electronic properties easily changed • Mechanism realistic models exist not obvious

  5. kinetic • • choosing the catalyst and comparing the selectivity and activity of catalysts and their performance under optimum conditions for each catalyst; • • the determination of the optimum sizes and structure of catalyst grains and the necessary amount of the catalyst to achieve the specified values of the selectivity of the process and conversion of the starting products; • • the determination of the composition of all byproducts formed during the process; • • the determination of the stability of steady states and parametric sensitivity; that is, the influence of deviations of all parameters on the steady-state regime and the behavior of the reactor under unsteady state conditions; • • the study of the dynamics of the process and deciding if the process should be carried out under unsteady-state conditions; • • the study of the influence of mass and heat transfer processes on the chemical reaction rate and the determination of the kinetic region of the process; • • choosing the type of a reactor and structure of the contact unit that provide the best approximations to the optimum conditions.

  6. Batch reactors : a) glass, b) high pressure, c) in parallel mode

  7. Stirred tank reactors in a) batch, b) continuous mode.

  8. Plug Flow reactors A tubular reactor

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