化学催化第七章催化剂设计.ppt

Introduction Mesoporous molecular sieves (MMSs) M41S HMS and MSU SBA Properties High surface area Monodispersed pore diameters Stereoregular channels Introduction Introduction MMS in the design of catalytic materials Co-condensation of active species during the MMS synthesis Post-synthesis methods Ion-exchange Impregnation Adsorption Grafting of reactive metal complexes Deposition of clusters or layers of metal oxides or of metal clusters, Grafting of silanes MMS catalytic applications Hydrotreatment Alkylation Catalysis by anchored complexes Polymerization Immobilized enzymes and enzymatic activity Base catalyzed reactions Mature technologies Hydrotreatment, alkylation and polymerization New fields Supported enzyme catalysis, production of fine chemicals and the synthesis of chemicals of biological interest Hydrotreatment Hydrodesulfurization (HDS)（加氢脱硫） Hydrodenitrogenation (HDN)（加氢脱氮） Mild hydrocracking (MHC) of heavy feeds Hydrogenation of aromatics in different distillates （芳烃加氢） Hydrotreatment Hydrodesulfurization of dibenzothiophene Hydrodesulfurization of dibenzothiophene Hydrotreatment Higher activity Interaction of metals with extraframework aluminum species yielding metal films Better selectivity Avoid the overcracking Mild acidity of the MMSs support Fast diffusion of the products The mesostructured aluminas of MSU type should be interesting supports provided their hydrothermal resistance is meeting the requirements of the process Alkylation Friedel–Crafts reactions, such as alkylations and acylations Homogeneous acid catalysts ( AlCl3, BF3 and H2SO4 ) Heterogenizing the catalysts Shape selective catalysts for bulk molecules Selectivity for the alkylation of benzene with 1-alkenes in the homogeneously (free AlCl3) and heterogeneously (MCM-41 supported AlCl3) catalyzed reactions Alkylation Alkylation Higher activity Adjustable acidity Better selectivity Controlable pore diameter Acidic mesoporous molecular sieves are good