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Scientific co-operation with professor Nazimek

Scientific co-operation with professor Nazimek 10.2478/v10063-011-0010-1 ANNALES UNIVERSITATIS MARIAE CURIE-SKLODOWSKA LUBLIN ­ POLONIA VOL. LXVI, 1, 2 SECTIO AA 2011 University of Maria Curie-Sklodowska, Department of Chemical Technology Pl. M. Curie-Sklodowskiej 3, 20-031 Lublin, Poland e-mail: janusz.ryczkowski@umcs.eu In present paper there will be discussed examples of author's scientific co-operation with professor Nazimek. Generally all of them are from the area of heterogeneous catalysis including high dispersed metal phase mostly in the hydrogenolysis reactions of simple alkanes. 1. INTRODUCTION The impact of catalysis and catalysts is substantial. Today over 90% of all industrial chemicals are produced with the aid of catalysts [1,2]. Catalysts impact a sizable fraction of any nation's gross domestic product [2]. The story of catalysis has been told in the past by practitioners with different perspectives [2]. Lindstrom and Pettersson [3] chose to look at the development of catalysis over periods of time back to the dawn on civilization. This was the base of drawing scheme presented below (Figure 1) [4,5]. Taking into account published data [3-5], in present paper there will be discussed facts which took place in the 7th period of catalysis development. This article is dedicated to Professor Dobieslaw Nazimek on the occasion of his th 65 birthday Fig. 1. Historical development of catalysis [4,5]. 2. BACKGROUND The classical definition of chemistry is as follows: chemistry is the study of the composition and properties of matter, the transformations they undergo, and the associated energies. In this respect an applied chemistry is the application of the theories and principles of chemistry to practical purposes. All discussed examples fit well into this category [6-25]. As it is shown in Figure 2, all indicated sub-constituents are named in a classical way and cover broad areas of heterogeneous catalysis. Moreover, there is strong correlation between them. Fig. 2. Areas of author's scientific co-operation with professor Nazimek ­ simplified scheme. 3. MEAN CRYSTALLITE SIZE The activity and selectivity of a supported metal catalyst are strongly influenced by the amount of metal, the size of dispersed metal particles, the preparation method and the support composition. To improve the catalyst activity and its durability, it is necessary to obtain a well dispersed active phase in the catalyst. In our laboratory an original technique of obtaining metal catalysts characterized by small metal crystallites, the so-called double impregnation method (DIM) was elaborated [26,27]. In contrast to the classical impregnation method (CIM), in the DIM preparation procedure the support is preliminary "activated" (modified) by EDTA (Figure 3). Fig. 3. Scheme of catalyst preparation by DIM (° - H2Na2EDTA, · - different Mn+ and M + species; where M is a metal; LTT ­ low temperature treatment, HTT ­ high temperature treatment) resulted in high dispersion of the metal in the final catalyst [5]. This preparation procedure allows to obtain high dispersed (according to the calculations of the mean crystallite size) and stable (after high temperature treatment) metal supported catalysts [6-9,14,15,17,21]. Mentioned above catalyst preparation technique (DIM) was utilized in the preparation of some metal supported (Figure 4) catalysts following applied in the catalytic reactions [6-9, 11,14-16, 20, 24]. Fig. 4. Investigated metals (bolded) as a high dispersed active phase in the studied catalysts. 4. HYDROGENOLYSIS Apart from investigating the problems of the kinetics and mechanisms of hydrocarbon hydrogenolysis, catalytic studies often concern general questions of catalysis such as the effect of metal content and the correlation between the catalytic properties and the electronic and structural changes in metals. With supported catalysts, attention has usually been focused on examining the effect of the degree of dispersion, that is, crystallite size, on the electronic properties and reactivity of various systems [6-9,11,14-16,24]. In many papers it has been found that an increased dispersion of crystallites of Group 8-10 metals causes changes in the number and quality of the complex of active centers on its surface. Some scientists suggested that B5 centers may play a special role in alkane hydrogenolysis (Figure 5). Fig. 5. Microscopic view of a metal surface (a) and alternative B5 site geometries (b) formed at terrace edges on (111) and (100) planes [28,29]. In the research conducted [6-9,11,14-16,24] we studied the effects of metal (nickel, platinum, rhodium) dispersion and changes in the number of B5 centers on the course of simple hydrocarbons (ethane, propane and n-butane) hydrogenolysis. 5. MODIFIERS AND CATALYSTS Simple and the cheapest way of the catalysts quality improvement is an introduction of promoters. It turns out, that the small amount of additives introduced into the catalysts' formula have a great influence on their textural properties, activity, selectivity and lifetime. Promoters can be classed as substances which, when added to a catalyst as a minor component, improve one or more of the properties of the material with respect to product formation. However, in the literature dealing with the catalytic problems there is no quantative determination of "small amount" or "minor component". It seems, that the amount will vary with the catalyst (or reaction), and the precise determination of the standard value for the whole systems and processes is impossible [30]. Promoters belongs to the class of positive (+) modifiers (Figure 6). Fig. 6. Division of modifiers based on modifier action type [30,31]. A condensed summary of the scientific activity in the area of modifiers application is given in Table 1. Tab. 1. Examples of applied modifiers in our research [10-13,16,18-20,23]. Catalyst/support Ni/ -Al2O3 Ni/ -Al2O3 Ni/ -Al2O3 Ni/ -Al2O3 Ni/ -Al2O3 -Al2O3 -Al2O3 Pt/ -Al2O3 various Modifier/adsorbat* organic compounds organic compounds H4EDTA, H2Na2EDTA organic compounds H2Na2EDTA, Sn H2Na2EDTA, H2(NH4)2EDTA Na2IDA, Na3NTA Cu, Ag, Au H2Na2EDTA, W, Mo Comment** physico-chemical studies hydrogenolysis of n-butane IR studies hydrogenolysis of n-butane FT-IR/PAS studies, hydrogenolysis of simple alkanes FT-IR studies FT-IR studies hydrogenolysis of n-butane short review Reference [10] [11] [12] [13] [16] [18] [19] [20] [23] * ­ EDTA ­ ethylenediaminetetraacetic acid, IDA ­ iminodiacetic acid, NTA ­ nitrilotriacetic acid; ** ­ IR ­ infrared, FT-IR ­ fourier transform infrared, PAS ­ photoacoustic spectroscopy. 6. GRADIENTLESS REACTOR To undertake reaction studies on both pellets or very fine catalyst particles, an internal reactor was constructed of stainless steel (Figure 7) [22,24]. Fig. 7. Schematic diagrams of various versions of gradientless reactor: 1 ­ impeller, 2 ­ catalyst bed, 3,4 ­ thermocouple shields [22]. Construction details are given elsewhere [22,24,32]. 7. SUMMARY Instead of a typical summary let me present a pictorial conclusion (Figure 7) based on the picture presented by A. Baiker (major directions of research and their interdependence) [33]. Fig. 7. Major directions of professor Nazimek scientific life activities and their interdependence. 8. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Annales UMCS, Chemia de Gruyter

Scientific co-operation with professor Nazimek

Annales UMCS, Chemia , Volume 66 – Jan 1, 2011

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Abstract

10.2478/v10063-011-0010-1 ANNALES UNIVERSITATIS MARIAE CURIE-SKLODOWSKA LUBLIN ­ POLONIA VOL. LXVI, 1, 2 SECTIO AA 2011 University of Maria Curie-Sklodowska, Department of Chemical Technology Pl. M. Curie-Sklodowskiej 3, 20-031 Lublin, Poland e-mail: janusz.ryczkowski@umcs.eu In present paper there will be discussed examples of author's scientific co-operation with professor Nazimek. Generally all of them are from the area of heterogeneous catalysis including high dispersed metal phase mostly in the hydrogenolysis reactions of simple alkanes. 1. INTRODUCTION The impact of catalysis and catalysts is substantial. Today over 90% of all industrial chemicals are produced with the aid of catalysts [1,2]. Catalysts impact a sizable fraction of any nation's gross domestic product [2]. The story of catalysis has been told in the past by practitioners with different perspectives [2]. Lindstrom and Pettersson [3] chose to look at the development of catalysis over periods of time back to the dawn on civilization. This was the base of drawing scheme presented below (Figure 1) [4,5]. Taking into account published data [3-5], in present paper there will be discussed facts which took place in the 7th period of catalysis development. This article is dedicated to Professor Dobieslaw Nazimek on the occasion of his th 65 birthday Fig. 1. Historical development of catalysis [4,5]. 2. BACKGROUND The classical definition of chemistry is as follows: chemistry is the study of the composition and properties of matter, the transformations they undergo, and the associated energies. In this respect an applied chemistry is the application of the theories and principles of chemistry to practical purposes. All discussed examples fit well into this category [6-25]. As it is shown in Figure 2, all indicated sub-constituents are named in a classical way and cover broad areas of heterogeneous catalysis. Moreover, there is strong correlation between them. Fig. 2. Areas of author's scientific co-operation with professor Nazimek ­ simplified scheme. 3. MEAN CRYSTALLITE SIZE The activity and selectivity of a supported metal catalyst are strongly influenced by the amount of metal, the size of dispersed metal particles, the preparation method and the support composition. To improve the catalyst activity and its durability, it is necessary to obtain a well dispersed active phase in the catalyst. In our laboratory an original technique of obtaining metal catalysts characterized by small metal crystallites, the so-called double impregnation method (DIM) was elaborated [26,27]. In contrast to the classical impregnation method (CIM), in the DIM preparation procedure the support is preliminary "activated" (modified) by EDTA (Figure 3). Fig. 3. Scheme of catalyst preparation by DIM (° - H2Na2EDTA, · - different Mn+ and M + species; where M is a metal; LTT ­ low temperature treatment, HTT ­ high temperature treatment) resulted in high dispersion of the metal in the final catalyst [5]. This preparation procedure allows to obtain high dispersed (according to the calculations of the mean crystallite size) and stable (after high temperature treatment) metal supported catalysts [6-9,14,15,17,21]. Mentioned above catalyst preparation technique (DIM) was utilized in the preparation of some metal supported (Figure 4) catalysts following applied in the catalytic reactions [6-9, 11,14-16, 20, 24]. Fig. 4. Investigated metals (bolded) as a high dispersed active phase in the studied catalysts. 4. HYDROGENOLYSIS Apart from investigating the problems of the kinetics and mechanisms of hydrocarbon hydrogenolysis, catalytic studies often concern general questions of catalysis such as the effect of metal content and the correlation between the catalytic properties and the electronic and structural changes in metals. With supported catalysts, attention has usually been focused on examining the effect of the degree of dispersion, that is, crystallite size, on the electronic properties and reactivity of various systems [6-9,11,14-16,24]. In many papers it has been found that an increased dispersion of crystallites of Group 8-10 metals causes changes in the number and quality of the complex of active centers on its surface. Some scientists suggested that B5 centers may play a special role in alkane hydrogenolysis (Figure 5). Fig. 5. Microscopic view of a metal surface (a) and alternative B5 site geometries (b) formed at terrace edges on (111) and (100) planes [28,29]. In the research conducted [6-9,11,14-16,24] we studied the effects of metal (nickel, platinum, rhodium) dispersion and changes in the number of B5 centers on the course of simple hydrocarbons (ethane, propane and n-butane) hydrogenolysis. 5. MODIFIERS AND CATALYSTS Simple and the cheapest way of the catalysts quality improvement is an introduction of promoters. It turns out, that the small amount of additives introduced into the catalysts' formula have a great influence on their textural properties, activity, selectivity and lifetime. Promoters can be classed as substances which, when added to a catalyst as a minor component, improve one or more of the properties of the material with respect to product formation. However, in the literature dealing with the catalytic problems there is no quantative determination of "small amount" or "minor component". It seems, that the amount will vary with the catalyst (or reaction), and the precise determination of the standard value for the whole systems and processes is impossible [30]. Promoters belongs to the class of positive (+) modifiers (Figure 6). Fig. 6. Division of modifiers based on modifier action type [30,31]. A condensed summary of the scientific activity in the area of modifiers application is given in Table 1. Tab. 1. Examples of applied modifiers in our research [10-13,16,18-20,23]. Catalyst/support Ni/ -Al2O3 Ni/ -Al2O3 Ni/ -Al2O3 Ni/ -Al2O3 Ni/ -Al2O3 -Al2O3 -Al2O3 Pt/ -Al2O3 various Modifier/adsorbat* organic compounds organic compounds H4EDTA, H2Na2EDTA organic compounds H2Na2EDTA, Sn H2Na2EDTA, H2(NH4)2EDTA Na2IDA, Na3NTA Cu, Ag, Au H2Na2EDTA, W, Mo Comment** physico-chemical studies hydrogenolysis of n-butane IR studies hydrogenolysis of n-butane FT-IR/PAS studies, hydrogenolysis of simple alkanes FT-IR studies FT-IR studies hydrogenolysis of n-butane short review Reference [10] [11] [12] [13] [16] [18] [19] [20] [23] * ­ EDTA ­ ethylenediaminetetraacetic acid, IDA ­ iminodiacetic acid, NTA ­ nitrilotriacetic acid; ** ­ IR ­ infrared, FT-IR ­ fourier transform infrared, PAS ­ photoacoustic spectroscopy. 6. GRADIENTLESS REACTOR To undertake reaction studies on both pellets or very fine catalyst particles, an internal reactor was constructed of stainless steel (Figure 7) [22,24]. Fig. 7. Schematic diagrams of various versions of gradientless reactor: 1 ­ impeller, 2 ­ catalyst bed, 3,4 ­ thermocouple shields [22]. Construction details are given elsewhere [22,24,32]. 7. SUMMARY Instead of a typical summary let me present a pictorial conclusion (Figure 7) based on the picture presented by A. Baiker (major directions of research and their interdependence) [33]. Fig. 7. Major directions of professor Nazimek scientific life activities and their interdependence. 8.

Journal

Annales UMCS, Chemiade Gruyter

Published: Jan 1, 2011

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