Catalysis microporous materials

Volume 94 Catalysis by Microporous Materials. Proceedings of ZEOCAT 95, Szombathely,... 

The mesoscopic domain of real catalysts is mostly covered by the typical catalysis periodicals, such as Applied Catalysis, the Journal of Catalysis, Catalysis Letters, Topics in Catalysis, Catalysis Today, Microporous Materials and Zeolites, although occasionally articles also appear in Journal of Physical Chemistry and Physical Chemistry-Chemical Physics, and many others. 

H.H. Mooiweer, K.P. de Jong, B. Kraushaar-Czarnetzki, W.H.J. Stork and B.C.H. Krutzen, "Zeolites nd Related Microporous Materials State of The Art 1994", Studies in Surface Science and Catalysis, Elsevier, 1994, Eds. 

R. Hoppe, G. Schulz-Ekloff, D. Wohrle, C. Kirschhock, and H. Fuess, in Zeolites and Related Microporous Materials State of the Art 1994. Studies in Surface Science and Catalysis, J. Weitkamp, H. G. Karge, H. Pfeifer, W. Holderich, Eds., Elsevier, Amsterdam, 1994, Vol. 84, pp. 821-827. 

There are, however, two limitations associated with preparation and application of zeolite based catalysts. First, hydrothermal syntheses Umit the extent to which zeolites can be tailored with respect to intended appUcation. Many recipes involving metals that are interesting in terms of catalysis lead to disruption of the balance needed for template-directed pore formation rather than phase separation that produces macroscopic domains of zeoUte and metal oxide without incorporating the metal into the zeohte. When this happens, the benefits of catalysis in confined chambers are lost. Second, hydrothermal synthesis of zeoHtic, silicate based soHds is also currently Hmited to microporous materials. While the wonderfully useful molecular sieving abihty is derived precisely from this property, it also Hmits the sizes of substrates that can access catalyst sites as weU as mass transfer rates of substrates and products to and from internal active sites. 

Taguchi A, Schiith F (2005) Ordered mesoporous materials in catalysis. Microporous Mesoporous Mater 77(1) 1 5... 

Zeolites are the most promising microporous materials for achieving highly shape-selective catalysis because their pores are uniformly distributed and have dimensions allowing both the organic reactants and products to enter, to react, and to leave.1... 

Micropores are smaller than 2 nm. In micropores the structure of the adsorbed fluid is significantly different from its macroscopic bulk structure. Confined liquids are a highly active area of research because of their unique properties. An important example of a microporous materials are zeolites, which are used for catalysis. 

Jansen JC, Koegler JH, Bekkum Hv, Calis HP, Bleek CM, Kapteijn F, Moulijn JA, Geus ER, Puil Nvd. Zeolitic coatings and their potential use in catalysis. Microporous Mesoporous Materials 1998 21 213-226. 

Porous oxide catalytic materials are commonly subdivided into microporous (pore diameter <2nm) and mesoporous (2-50 nm) materials. Zeolites are aluminosilicates with pore sizes in the range of 0.3-1.2 nm. Their high acidic strength, which is the consequence of the presence of aluminium atoms in the framework, combined with a high surface area and small pore-size distribution, has made them valuable in applications such as shape-selective catalysis and separation technology. The introduction of redox-active heteroatoms has broadened the applicability of crystalline microporous materials towards reactions other than acid-catalysed ones. 

M Hermann, W Niessen, H G Karge m Catalysis by Microporous Materials, (Eds H K Beyer, H G Karge, I Kincsi, J B Nagy), Elsevier, Amsterdam, 1995... 

Zeolites and related aluminosilicates constitute a vital family of microporous materials with immense applications in catalysis, sorption and separation processes [1-3]. The discovery of aluminophosphates is an important landmark in the science of these materials [4], All these materials are, in general, synthesized under hydrothermal conditions by making use of template molecules [2]. The template molecules are usually organic amines and they are involved in the formation of these framework structures in more ways than one. While it is difficult to pinpoint the exact manner in which the amines participate or direct the formation of these inorganic structures, it is generally believed that their size and shape are crucial in determining the pore structure. In recent years, a variety of open-framework structures formed by divalent metal phosphates... 

Souverijns W. et al., Progress in Zeolite and Microporous Materials, Studies in Surface Science and Catalysis, 105 (1997) 1285. 

Venuto P.B., Organic Catalysis Over Zeolites A Perspective On Reaction Paths Within Micropores, Review presented at Symposium On New Catalytic Chemistry Utilizing Molecular Sieves, ACS National Meeting, Chicago, 1993 And Symposium Proceedings Microporous Materials. 2 (1994) 297-411. 

---