23-P-27 - T h e use of M C M - 2 2 as catalyst for the B e c k m a n n - r e a r r a n g e m e n t of c y c l o h e x a n o n e oxime to s-caprolactam G. Dahlhoff, U. Barsnick, W. Eickelberg and W.F. H61derich Heterogeneous Catalysis, RWTH, Aachen, [email protected]
, Germany A variety of catalysts have been applied to the Beckmann-rearrangement of cyclohexanone oxime to s-caprolactam. Experiments with MFI structures yielded good results showing the importance of weak acidic sites, a large outer surface and pore structure accessible only through 10MR channels. Recent reports recommended the MCM-22 catalyst with its large outer surface and special structure for the use in the Beckmann-rearrangement. In the present study the synthesis and brief characterisation of MCM-22 was carried out followed by the first in depth analysis of its applicability for the Beckmann rearrangement of cyclohexanone oxime to s-caprolactam. The performance of the material was compared to one of the established catalysts - the [B]-MFI - showing several drawbacks like lower yields.
23-P-28 - Nickel supported on zirconium doped m e s o p o r o u s silica as catalysts for the gas phase hydrogenation of acetonitrile P. Braos-Garcia, L. Diaz, P. Maireles-Torres, E. Rodriguez-Castelldn and A. Jim~nez-L6pez Departamento de Quimica Inorgdnica, Cristalografia y Mineralogia, Facultad de Ciencias, Universidad de Mdlaga, Campus de Teatinos, 29071 M~ilaga (Spain) Gas-phase hydrogenation of acetonitrile has been studied by using catalysts based on nickel supported on zirconium doped mesoporous silica. All catalysts are active in this catalytic reaction, but the activity decreases with the time, being more stable when increasing the nickel loading. After catalytic reaction, all catalysts contain nitrogen and carbon, being their percentages higher for shorter times of deactivation. Nevertheless, the activity and selectivity patterns are totally recovered after treatment with H2 at high temperature, which indicates that these nitrogen and carbon species can be totally removed from the surface of catalysts by hydrogenation.
23-P-29 - Synthesis of fine chemicals intermediates over basic zeolites C.O. Veloso a, A.C. Pinto b, E.N. Santos c and J.L.F. Monteiro a ~NUCAT/COPPE, Universiclade Federal do Rio de Janeiro, [email protected]
6IQ, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil ClCEx, Universidade Federal de Minas Gerais, Minas Gerais, Brazil X zeolites exchanged with cesium and impregnated with cesium species were active as catalysts for the Knoevenagel reaction between the aldehyde obtained by the hydroformylation of limonene and ethyl acetoacetate. The product distribution observed has shown that other reactions were occurring, such as decarboxilation and aldol condensation reactions that also led to products of potential commercial interest. The best results were obtained for the sample with 14 cesium atoms impregnated per unit cell, at 403 K and ethyl acetoacetate / menthene molar ratio of 5. In such a condition, yields of products of interest as intermediates for fine chemicals production were as high as 90% after 4 h of reaction.