Papers
More filters
TL;DR: In this paper, a controlled reduction in the effective dimensions of the catalyst pore openings, and/or channels, along with deactivation of acidic surface sites, has been proposed as a mechanism for the selective production of p-xylene.
513 citations
Cited by
More filters
TL;DR: A broad classification and survey of organic chemistry over zeolites is presented in this paper, which reflects, for the most part, a mechanistic rather than a process or applications frame of reference.
564 citations
TL;DR: The shape-selective catalysis as discussed by the authors was proposed to increase the selectivity of a desired product and reduce the coke formation in zeolite catalysts by reducing the number of catalytic sites inside the pore structure.
556 citations
TL;DR: The application of zeolite-based catalysts in the production of chemicals and fine chemicals is an emerging field, and will greatly depend on the discovery of new or known structures by alternative, lower cost, synthesis routes, and the fine tuning of their textural properties as mentioned in this paper.
549 citations
TL;DR: This review considers the mixed molecular-nanostructure approach that can be used to develop more demanding catalytic sites, by derivatizing the surface of solids or tethering or immobilizing homogeneous catalysts or other chemical functionalities.
Abstract: In this review, a brief survey is offered on the main nanotechnology synthetic approaches available to heterogeneous catalysis, and a few examples are provided of their usefulness for such applications. We start by discussing the use of colloidal, reverse micelle, and dendrimer chemistry in the production of active metal and metal oxide nanoparticles with well-defined sizes, shapes, and compositions, as a way to control the surface atomic ensembles available for selective catalysis. Next we introduce the use of sol–gel and atomic layer deposition chemistry for the production and modification of high-surface-area supports and active phases. Reference is then made to the more complex active sites that can be created or carved on such supports by using organic structure-directing agents. We follow with an examination of the ability to achieve multiple functionality in catalysis via the design of dumbbells, core@shell, and other complex nanostructures. Finally, we consider the mixed molecular-nanostructure approach that can be used to develop more demanding catalytic sites, by derivatizing the surface of solids or tethering or immobilizing homogeneous catalysts or other chemical functionalities. We conclude with a personal and critical perspective on the importance of fully exploiting the synergies between nanotechnology and surface science to optimize the search for new catalysts and catalytic processes.
535 citations
01 Jan 1983
TL;DR: In this paper, a study was made of the selectivity of zeolite catalysts due to the shape and size of their pore diameters, and they had pores with one or more discreet sizes.
Abstract: A study was made of the selectivity of zeolite catalysts due to the shape and size of their pores. Typically, their pore diameters are less than 10 angstroms, and they have pores with one or more discreet sizes. The shape and size of zeolite pores can control reactions by limiting travel of reactants or products that are larger than the pores, or by the limiting size of the cavities being smaller than a transition state of a reaction. Also included were descriptions of control and applications of shape selectivity of porous zeolite catalysts. Seven illustrations and 53 references were included.
475 citations