Lewis Acids: From Conventional Homogeneous to Green Homogeneous and Heterogeneous Catalysis

Organic catalysis over zeolites: A perspective on reaction paths within micropores

Shape-selective catalysis in zeolites

Inorganic molecular sieves: Preparation, modification and industrial application in catalytic processes

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.

Nanostructured materials for applications in heterogeneous catalysis

Selective alkylation of toluene with methanol to produce para-xylene

Shape selective reactions with zeolite catalysts: III. Selectivity in xylene isomerization, toluene-methanol alkylation, and toluene disproportionation over ZSM-5 zeolite catalysts

Shape-selective reactions with zeolite catalysts: II. Selective disproportionation of toluene to produce benzene and p-Xylene

Process for the selective production of para-xylene by methylation of toluene in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12 which catalyst has undergone prior treatment with steam to reduce the alpha value thereof to less than about 500 and preferably within the range of less than about 20 but greater than zero.

Selective production of para-xylene

There is disclosed a method for decreasing catalyst coking and extending the usable catalyst life by pre-treatment of the catalyst with steam and/or a phosphorus-containing compound. Catalysts benefiting from such pre-treatment comprise crystalline zeolites characterized by a silica to alumina mole ratio of at least 12 and a constraint index, as herein defined, within the approximate range of 1 to 12.

Lewis B. Young

Papers

Selective alkylation of toluene with methanol to produce para-xylene

Shape selective reactions with zeolite catalysts: III. Selectivity in xylene isomerization, toluene-methanol alkylation, and toluene disproportionation over ZSM-5 zeolite catalysts

Shape-selective reactions with zeolite catalysts: II. Selective disproportionation of toluene to produce benzene and p-Xylene

Selective production of para-xylene

Extending catalyst life by treating with phosphorus and/or steam