DE102018129499A1 - Composite material in the form of solid particles with core-shell active phase structure, process for obtaining such composite material and its use - Google Patents

Abstract

The invention relates to a composite material in the form of solid particles having a core-shell active phase structure comprising a core of adsorbent material, at least one inorganic oxide and particles of the catalytically active phase and characterized in that the adsorption material is porous carbon, the inorganic oxide in that the core shell and the carrier agent form the catalytically active phase selected from the group consisting of zirconium oxide, titanium oxide, alumina, cerium oxide, the catalytically active phase consists of nanoparticles and their agglomerates based on metals or metal oxides prepared from the Pt, Pd , Rh, Re, Ir, Au, CoO, CuO, MnO, MnO, MnO, CeO, NiO, ZnO, FeO or mixtures thereof. The invention also provides the process for obtaining such a composite material and its use for the elimination of volatile organic compounds by adsorption and their subsequent catalytic oxidation.

Description

The invention relates to a composite material in the form of solid particles having a core-shell active phase structure, processes for obtaining such a composite material and its use for the elimination of volatile organic compounds.

The emission of volatile organic compounds (VOCs) into the atmosphere from both natural and anthropogenic sources is one of the most serious threats to human health and the environment. These substances interact directly and indirectly with the constituents of the atmosphere, causing photochemical reactions to occur; Several times they have carcinogenic and mutagenic properties. Reduction in VOC emissions can be realized by controlling industrial sources (eg, exhaust fumes produced by dyers, paint shops, pharmaceutical companies, and bakeries) that produce nearly half of the total amount of VOCs released by human activity. In addition to the primary methods that seek to limit the emission levels of volatile organic compounds, a number of solutions have been developed involving binding (non-destructive techniques) or harmless (destructive) techniques of VOCs contained in the air. The most commonly used techniques include: thermal and catalytic oxidation, adsorption, condensation and membrane separation.

Adsorption of volatile organic compounds

Because of the high efficiency, low cost operation of necessary equipment, and environmentally friendly character, adsorption is a basic method for removing VOCs from low emission sources. In addition, during recovery from the spent adsorbent, there is an opportunity to recover the previously linked molecules and reuse them. The most widely used VOC adsorbents are carbon materials based on activated carbon derived from fossil carbons or biomass. However, polymers (eg polyacrylonitrile, polyvinyl chloride, polyfurfyl alcohol, resole resins) are becoming increasingly important in activated carbon production. The advantage of using synthetic polymeric materials is the recovery of activated carbons that have a repeatable composition and a low ash content. Activated carbons are obtained by the pyrolysis process (carbonization) of the starting material, which is carried out at high temperatures in a neutral atmosphere with a subsequent physical or chemical activation of the product obtained. The purpose of the first activation path is to increase the porosity and the specific surface area of the activated carbon by removing carbon-free elements. The second method, however, serves to generate corresponding surface properties. For chemical activation, steam or carbon dioxide is usually used, while physical activation is most often carried out in the presence of KOH, ZnCl ₂ or H ₃ PO ₄ . The activated carbons obtained in the manner described above are microporous materials having a highly developed specific surface area.

In recent years, porous carbon materials having spherical particles ranging in diameter from several tens of nanometers to several tens of micrometers, particularly for adsorptive, medical (excipient) and electrochemical (electrode materials) uses have been intensively researched. Such materials are synthesized primarily using: (i) methods for the hydrothermal modification of saccharides and its copolymers (e.g., with phenolic derivatives), (ii) soft organic forming techniques, and (iii) pathways of structurally imprinting spherical silica -Materials. The synthesis of spherical carbon materials according to the first of these approaches consists in the initial dehydrogenation of the carbon precursor (eg glucose, xylose, fructose, mixture of xylose and phenol) under hydrothermal conditions (140-210 ° C), optional activation (eg using KOH), followed by carbonization in the presence of inert gas (eg, argon or nitrogen) at temperatures in the range of 600-1000 ° C. The materials obtained in this way are characterized by specific surface area in the range of 13 (without activation) to about 1280 m ² / g (after KOH activation), which results mainly from the presence of irregularly ordered micropores [M. , Li, W. Li, S. Liu, Hydrothermal synthesis, characterization, and KOH activation of carbon spheres from glucose, Carbohydrate Research 346 (2011) 999-1004; J. Ryu, Y.-W. Suh, DJ Suh, DJ Ahn, Hydrothermal preparation of carbon microspheres from mono-saccharides and phenolic compounds, Carbon 48 (2010) 1990-1998; Q. Wang, H. Li, L. Chen, X. Huang, Monodispersed hard carbon spherules with uniform nanopores, Carbon 39 (2001) 2211-2214].

Unlike the above-mentioned technique, the solutions using organic or inorganic structure-forming templates allow carbon materials with an ordered system of To obtain pores of controllable size, including mesoporous arrangements. The advantage of the mesoporous activated carbon obtained by the template shaping processes is the substantial width of the homogeneous pores (at a comparable specific surface area with conventional activated carbons), which eliminates the diffusion limitations in adsorptive or catalytic uses. In the soft-template method, surfactants are mainly block copolymers (eg, Pluronic F127, Pluronic P123) or alkylammonium halide, which form micelle-built matrices in / at which the carbon precursor the polymerization is (most often phenol-formaldehyde resins) [M. Li, J. Xue, Ordered mesoporous carbon nanoparticles with well-controlled morphologies from sphere to rod via a soft-template route, Journal of Colloid and Interface Science 377 (2012) 169-175; J. Liu, T. Yang, D.-W. Wang, G. Qing (Max) Lu, D. Zhao, SZ Qiao, A facile soft-template synthesis of mesoporous polymeric and carbonaceous nanospheres, Nature Communications 4 (2013) 2798]. The spherical shape of the resulting particles is recovered by the use of the appropriate amount of a surfactant or cosurfactant. The resulting polymer is thermally modified in the presence of inert gas at temperatures in the range of 400-800 ° C. The carbon materials obtained by this technique exhibit the presence of ordered mesopores and are characterized by a specific surface area of 460-1380 m ² / g.

The technique most commonly described in the literature for the synthesis of coals with a spherical grain structure is the shaping of the spherical silica template (hard-template method). The typical process for synthesizing such carbon prints comprises: (i) obtaining the mesoporous silica globule with spherical particles, (ii) depositing the carbon precursor in the pore system of the silica, eg by impregnation, in situ polymerization or CVD deposition. (iii) carbonization of the resulting material in a neutral atmosphere at a temperature in the range of 800-1100 ° C to form the carbon-silica nanocomposite, and then (iv) removal of the silica template by means of strong alkali etching (e.g. B. NaOH) or HF. [M.-H. Kim, K.-B. Kim, SM. Park, KC Roh, Hierarchically structured activated carbon for ultracapacitors, Scientific Reports 6 (2016) 21182; M. Kim, SB Yoon, K. Sohn, JY Kim, C.-H. Shin, T. Hyeon, J.-S. Yu, Synthesis and characterization of spherical carbon and polymer capsules with hollow macroporous core and mesoporous shell structures, Microporous and Mesoporous Materials 63 (2003) 1-9; T.-W. Kim, P.-W. Chung, V S.-Y. Lin, Facile Synthesis of Monodisperse Spherical MCM-48 Mesoporous Silica Nanoparticles with Controlled Particle Size, Chemistry of. Materials 22 (2010) 5093-5104]. Commonly used as rigid matrices are commercially available, randomly ordered, silica-ordered porous silica gels and mesoporous ordered silica materials (e.g., SBA-15, SBA-16, MCM-41, MCM-48) made by the appropriate selection of surfactants Shape the ball to be shaped with a defined diameter. Resin resins, polyfurfyl alcohol, polyacrylonitrile and disaccharides (e.g., sucrose) [HI Melendez-Ortiz, LA Garcia-Cerda, Y. Olivares-Maldonado, G. Castruita, JA Mercado-Silva., Et al., As carbon precursors, are similar to those described above , YA Perera-Mercado, Preparation of spherical MCM-41 molecular sieve at room temperature: Influence of the synthesis conditions in the structural properties, Ceramics International 38 (2012) 6353-6358; T.-W. Kim, P.-W. Chung, V S.-Y. Lin, Facile Synthesis of Monodisperse Spherical MCM-48 Mesoporous Silica Nanoparticles with Controlled Particle Size, Chemistry of Materials 22 (2010) 5093-5104; MA Ballem, EM Johansson, JM Córdoba, M. Oden, Synthesis of hollow silica spheres SBA-16 with large-pore diameter, Materials Letters 65 (2011) 1066-1068; A. Katiyar, S. Yadav, PG Smirniotis, NG Pinto, Synthesis of ordered large pore SBA-15 spherical particles for adsorption of biomolecules, Journal of Chromatography A 1122 (2006) 13-20]. In order to improve the performance characteristics, the carbon materials obtained by the above techniques may be subjected to subsequent physical or chemical activation by similar methods to those used for activated carbon from natural sources, for example, by partial gasification of the carbon material with a gaseous one Agent (eg steam, carbon dioxide) or chemical activation with a hydroxide solution (eg KOH, NaOH) or an acid solution (eg H ₃ PO ₄ , HNO ₃ ).

Catalytic oxidation of volatile organic compounds

In addition to adsorptive technologies, catalytic post-combustion of VOCs is a widely used method for its removal from the gas phase. The catalysts used in this process usually contain a small amount of noble metals (eg Pt, Pd, Au or Rh), which as active phase high power efficiency, thermal stability and selectivity in the recovery of desired reaction products (mainly H ₂ O and CO ₂ ). However, due to high manufacturing costs and poisoning, intensive research is being undertaken to find alternative, catalytically active materials in the VOCs post-combustion process. Examples of such arrangements are catalysts containing oxides of transition metals and mixtures thereof (eg, CuO, Co ₃ O ₄ , MnO ₂ , Fe ₂ O ₃ , CeO ₂ ), which may be replaced by high poisoning resistance (including with sulfur containing compounds) and lower manufacturing costs compared to noble metal based catalysts. Because of the favorable influence of the development of the specific surface on the Kalatysatorsaktivität the active phase is applied to a carrier having a correspondingly selected porosity, ie an exposed surface has (eg., Γ-Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Zeolites, natural aluminum silicates, porous silica gel) [R. Arroyo, G. Cordoba, J. Padilla, VH Lara, Influence of manganese ions on the anatase - rutile phase transition of TiO ₂ prepared by the sol-gel process. Materials Letters 54 (2002) 397-402; MR Moreles, BP Barbero, T. Lopez, LE Cadus, H. Moreng: Evoluantion and characterization of Mn-Cu mixed oxide catalyst supported on TiO ₂ and ZrO ₂ for ethanol total oxidation. Fuel 88 (2009) 2120-2129, Á. Szegedi, M. Popova, K. Lázár, S. Klébert, E. Drotár, SBA-15 and SBA-16 materials on toluene oxidation, Microporous and Mesoporous Materials 177 (2013) 97-104; A. Rokicińska, P. Natkański, B. Dudek, M. Drozdek, L. Litynska-Dobrzyńska, P. Kustrowski, Co ₃ O ₄ -pillared montmorillonite catalysts synthesized by hydrogel-assisted route for total oxidation of toluene, Applied Catalysis B: Environmental 195 (2016) 59-68]. It has been shown that the tetragonal structure deposited on a ZrO ₂ substrate has greater activity with total oxidation of the VOCs than the catalysts supported on alumina, which is due to the greater reactivity of the oxygen present in the ZrO ₂ structure. To improve the catalytic properties, the materials deposited on the carrier are additionally modified with transition or noble metals [H.-J. Sedjame, C. Fontaine, G. Lafaye, J. Barbier Jr, On the promoting effect of the addition of ceria to platinum based alumina catalysts for VOC oxidation, Applied Catalysis B: Environmental 144 (2014) 233-242; JC Rooke, T. Barakat, M. Franco Finol, P. Billemont, G. De Weireld, Y. Lie, R. Cousin, J.-M. Giraudon, S. Siffert, J.-F. Lamonier, BL Su, Influence of hierarchically porous niobium doped TiO ₂ supports in the total catalytic oxidation of model VOCs on noble metal nanoparticles, Applied Catalysis B: Environmental 142-143 (2013) 149-160].

Examples of successful syntheses of ZrO ₂ based spherical materials in which this ingredient forms the core of the core or the shell have been described in the literature. In the first of these cases, the spherical porous particles of zirconium (IV) oxide are synthesized by the hydrothermal or sol-gel method or using soft and hard pattern-forming templates [Y. Chang, C. Wang, T. Liang, C. Zhao, X. Luo, T. Guo, J. Gong, H. Wu, Sol-gel Synthesis of Mesoporous Spherical Zirconia, RSC Advances 5 (2015) 104629-104634]. On the other hand, for the production of spherical ZrO ₂ shells, the so-called shell materials, the use of a spherical core is necessary, on whose surface a layer of ZrO ₂ precursor is deposited, for. B. by hydrolysis of zirconium or zirconyl alcoholates [H. Zhang, Z.-T. An, Q. Tang, W.-C. Li, Optimization design of novel spray reaction synthesis of mesoporous c-ZrO ₂ spherical particles, Journal of Computer-Aided Materials Design 14 (2007) 309-316]. Depending on the material used, the core can be removed by calcinacion (in the case of polymer particles) or etching (in the case of a silica core) [Y. Jiang, S. Yang, X. Ding, Y. Guo, H. Bala, J. Zhao, K. Yu, Z. Wang, Synthesis and catalytic activity of stable hollow ZrO ₂ -SiO ₂ spheres with mesopores in the shell wall, Journal of Materials Chemistry 15 (2005) 2041-2046; J. Yin, X. Qian, J. Yin, M. Shi, J. Zhang, G. Zhou, Preparation of polystyrene / zirconia core-shell microspheres and zirconia hollow shells, Inorganic Chemistry Communications 6 (2003) 942-945].

Composite materials having a core-shell active phase structure are known from the patent literature, including with respect to the adsorptive-catalytic function in the elimination of volatile organic compounds. For example, the international application discloses WO16069856A1 Catalysts of base metal for removing ozone, volatile organic compounds and other impurities from the air stream. The catalyst contains a shell, a substrate in the shell and a catalyst layer present on the substrate. The catalyst layer contains a first active ingredient in the form of a base metal, a second ingredient in the form of a base metal, and a substrate material impregnated with at least one of these ingredients. A preferred composition of the catalyst is the combination of manganese oxide and copper oxide.

In WO09157434A1 has described a method for purifying the carbon dioxide-containing exhaust gas, which consists in the post-combustion of VOCs and sulfur compounds in the presence of a catalyst containing one or a plurality of metal oxides selected from the group consisting of zirconium oxide, titanium oxide and silicon oxide or a plurality of noble metals selected from the group consisting of platinum, palladium and iridium.

The US patent application US2015057149A discloses catalysts and methods for obtaining catalysts for the oxidation of CO and / or volatile organic compounds. In one embodiment, the catalyst contains a reduced metal from the group of noble metals in an amount not exceeding 30% by weight. %, wherein the catalyst oxidizes volatile organic compounds and / or CO at a temperature of 150 ° C or lower. In a further embodiment, a catalyst for the oxidation of formaldehyde, formic acid and / or CO at a temperature of about 20 ° C to about 45 ° C at atmospheric pressure has been disclosed, wherein the catalyst contains a reduced metal from the group of precious metals on a carrier selected from the group consisting of CeO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , SiO ₂ and combinations thereof.

The in the Chinese patent CN103480369B described solution relates to a composite catalyst with nanometric platinum and its preparation and use. Many active sites of the catalyst formed by the Pt nanoparticles are deposited on the carrier in the form of SiO ₂ and thus form the structure of the SiO ₂ / Pt core. The outer surface of the SiO ₂ / Pt core is covered with a layer of mesoporous zirconia, thereby forming the core-shell structure SiO ₂ / Pt / ZrO ₂ . According to this invention, in reactions to recover aniline by hydrogenation of nitrobenzene and oxidation of carbon monoxide, the catalyst described can be used continuously or cyclically for more than 20 cycles, and the catalyst activity remains substantially unchanged. The catalyst is characterized by high activity, stability as well as the possibility of reuse and easy recovery. In addition, it is suitable for use in high temperature conditions due to the protective effect of the zirconia mesoporous shell.

The development of new composite materials that have such selected ingredients to ensure the appropriate material functionality is highly desired in a very rapidly evolving technology field such as materials science. The object of the present invention is to develop new-generation functional materials for both adsorption and catalytic applications in the field of VOC elimination.

• - poröser Kohlenstoff das Adsorptionsmaterial darstellt,
• - das anorganische Oxid, dass die Kernhülle und das Trägermittel der katalytisch aktiven Phase darstellt, aus der Zirkoniumoxid, Titaniumoxid, Aluminiumoxid, Ceroxid umfassenden Gruppe ausgewählt ist,
• - die katalytisch aktive Phase aus Nanopartikeln und ihren Agglomeraten auf Basis von Metallen oder Metalloxiden besteht, die aus der Pt, Pd, Rh, Re, Ir, Au, Co₃O₄, CuO, Mn₂O₃, MnO₂, Mn₃O₄, CeO₂, NiO, ZnO, Fe₂O₃ oder ihre Mischungen umfassenden Gruppe ausgewählt sind.

The invention relates to a composite material in the form of solid particles having a core-shell active phase structure, which comprises a core of adsorption material, at least one inorganic oxide and particles of the catalytically active phase, characterized in that

• porous carbon represents the adsorbent material,
• the inorganic oxide representing the core shell and the carrier of the catalytically active phase is selected from the group comprising zirconium oxide, titanium oxide, alumina, cerium oxide,
• - The catalytically active phase consists of nanoparticles and their agglomerates based on metals or metal oxides consisting of the Pt, Pd, Rh, Re, Ir, Au, Co ₃ O ₄ , CuO, Mn ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , CeO ₂ , NiO, ZnO, Fe ₂ O ₃ or mixtures thereof are selected.

Preferably, the solid particles of the composite material are spherical. Preferably, the solid particles have the diameter in the range of 50 nm to 500 microns.

The carbon core of the composite material is preferably a mesoporous carbon material having the specific surface area in the range of 200-2000 m ² / g and the pore volume in the range of 0.3 to 2.5 cm ³ / g. More preferably, the porous carbon core surface has a content of oxygen functional groups in the range of up to 15% by weight. O.

Preferably, the composite material is characterized in that the inorganic oxide is porous and the thickness of the shell of this oxide is in the range of 10-100 nm.

The composite material is preferably characterized in that the catalytically active phase is composed of metals or the metal oxides applied to the shell of the inorganic oxide and the shell itself. Preferably, metals or metal oxides which form the active phase are selected from the group comprising Pt, CuO, Co ₃ O ₄ . Preferably, the nanoparticles of the catalytically active phase are deposited on the surface of the inorganic oxide without contact with the carbon nucleus. Preferably, the amount of catalytically active metal in the final material is from 0.1 to 25.0% relative to the total mass of the oxygen shell.

1. a) Erhalten von porösem Kohlenstoffmaterial,
2. b) Aufbringen der Sauerstoffhülle auf den Kern aus porösem Kohlenstoffmaterial,
3. c) Abscheidung von den Partikeln der katalytisch aktiven Phase an die Sauerstoffhülle.

The invention also provides the process for obtaining the composite material described above, comprising the following steps:

1. a) obtaining porous carbon material,
2. b) applying the oxygen shell to the core of porous carbon material,
3. c) deposition of the particles of the catalytically active phase to the oxygen shell.

The method of obtaining the material is preferably characterized by performing step a) with the formation of the rigid silica templates where the carbon precursor is introduced into the silica matrix by impregnation, vapor deposition or in situ polymerization. The polymers obtained by in situ polymerization of monomers selected from the group consisting of the furfuryl alcohol, phenol-formaldehyde mixture and acrylonitrile are preferably the carbon precursor. Likewise preferred are the sugars selected from the group: sucrose, glucose and xylose of the carbon precursors.

Preferably, the method of obtaining the composite is characterized by the silica templates being based on silica gel or mesoporous silica materials of the SBA-15, SBA-16, MCM-41 and MCM-48 spherical particle form.

The method of obtaining the composite material is preferably characterized by obtaining porous carbon material by introducing the carbon precursor into the pore system of the spherical silica material to recover a polymer-silica composite which is subsequently carbonized at a temperature in the range of 600-1000 ° C under an inert gas atmosphere (argon, nitrogen, helium), and then the silica is removed from the carbon-silica material by etching with alkaline or acidic solution. Preferably, etching the silica from the carbon-silica composite results in modification of its surface, which is the generation of oxygen functional groups on the carbon surface. Preferably, the etching is carried out using NaOH having a concentration in the range of 1-5 M or of the HF solution having a concentration in the range of 1 to 10% at a temperature in the range 25-90 ° C to a correspondingly hydrophilic or to achieve hydrophobic character of the core surface.

Preferably, method of obtaining the composite material is characterized by performing the removal of silica before or after deposition from the shell of the inorganic oxide.

Preferably, the oxide shell is applied in the process in step b) by hydrolysis and polycondensation of a metal alcoholate in anhydrous alcohol solution in the presence of a surfactant.

Preferably, after step b) of the process, the material is dried and carbonated for 1 to 48 hours at a temperature in the range of 600-1000 ° C under an inert gas atmosphere, the temperature increasing at a rate of 0.1 to 50 ° C / min becomes.

The method for obtaining a composite material is preferably characterized in that the nanoparticles of the catalytically active phase in step c) are applied to the inorganic oxide layer by the impregnation method from a solution of a readily soluble compound of a selected metal.

The invention also relates to the use of the composite material described above for the elimination of the volatile organic compounds by adsorption in the core formed from porous carbon and their subsequent catalytic oxidation by the catalytically active phase present in the shell.

Preferably, the adsorption of volatile organic compounds takes place at a temperature in the range of 20-100 ° C, and the catalytic afterburning in the temperature range above 150 ° C. Preferably, the volatile organic compounds are selected from the group comprising aliphatic and aromatic hydrocarbons, alcohols, ketones, aldehydes and esters.

The term "composite material" refers to the composite material according to the invention.

For purposes of this description, the term "polymer-silica composite" refers to a material consisting of the silica skeleton and a carbon precursor-forming polymer incorporated therein, and "carbon-silica composite" or "carbon-silica material" a polymer-silica composite after the thermal modification in which the polymer part was carbonized.

The term "carbon print" refers to a carbon material obtained by removal from the silica-silica composite carbon dioxide template.

Commercially available means including, but not limited to, SBA-15, SBA-16, MCM-41, and MCM-48 silica materials, which may also be prepared by the synthetic method known to those skilled in the art, may be used to practice the invention.

Unless defined otherwise, all levels of ingredients in this specification are given in weight percentages (wt.%).

Thus, a new composite material has been developed within which the spherical core ("core") forming porous character carbon bond has been joined, the task of which is to ensure a high sorption capacity against VOCs in the adsorptive phase of the process (ambient temperature work). , By using various compounds to eliminate the silica template from the catalyst core precursor (including NaOH, HF), various concentrations of the solutions of these compounds, and various conditions (temperature, time of etching of the silica template) is the modification allows the surface of the shaped in the form of nanomicrometric spheres carbon core, which ensures the desired adsorption properties of this part of the composite material.

• - zur Eliminierung von polaren und unpolaren VOCs ist es bevorzugt, die Gegenwart der Gruppen mit einer hohen Hydrophilität (Sauerstoff-Funktionsgruppen) auf der Kohlenstoffkern-Oberfläche zu gewährleisten, was durch die Verwendung von NaOH als das die Siliciumdioxid-Matrize ätzende Agent erzielt wird,
• - zur Eliminierung von unpolaren VOCs, wie aliphatische und aromatische Kohlenwasserstoffe, ist es bevorzugt, die Gegenwart eines niedrigen Gehalts an Sauerstoff-Funktionsgruppen auf der Kohlenstoffkern-Oberfläche zu gewährleisten, was durch die Verwendung von HF während der Entfernung von der Siliciumdioxid-Matrize erzielt wird.

It is observed that, depending on the composite material used, e.g. For example, to eliminate a specific group of VOCs, particular modes of modification of the carbon core surface are desired:

• to eliminate polar and nonpolar VOCs, it is preferred to ensure the presence of the groups having high hydrophilicity (oxygen functional groups) on the carbon core surface, which is achieved by using NaOH as the silica matrix corrosive agent,
• to eliminate non-polar VOCs, such as aliphatic and aromatic hydrocarbons, it is preferred to ensure the presence of a low level of oxygen functional groups on the carbon core surface, which is achieved by the use of HF during removal from the silica die ,

Unlike other core-shell type materials where the core is based on porous carbon, the modification described above for this composite material is innovative and enormously important in achieving the object of the invention, as it allows control of the amount of superficial oxygen groups. which accounts for the high adsorptive capacity of the carbon core against the vapors of the polar VOCs. In addition, it allows the properties of the composite material to be tailored to the elimination of specific groups of VOCs compounds.

Nanomicrometric spherical carbon grains have been coated with a thin shell formed of an inorganic oxide, the purpose of which is to protect the carbon core during desorptive cycle catalytic work during VOC post-combustion (at an elevated temperature-controlled operating phase). , In addition, to improve the catalytic properties of the material, the porous inorganic shell has been modified to form a catalytically active phase in the form of nanometric metal particles (eg, Pt, Pd, Rh, Re, Ir, Au) or a transition metal oxide (For example, CuO, Co ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , CeO ₂ , Fe ₂ O ₃ ) or a mixture of said ingredients was applied to them. It should be emphasized that the catalytically active phase present in the composite according to the invention is not homogeneously distributed over the entire volume of the inorganic oxide shell, but remains mainly deposited on its surface. The transport of the molecules between the inner and outer part of the material is made possible by the use of a porous inorganic support from the group ZrO ₂ , Al ₂ O ₃ , TiO ₂ , CeO ₂ - in contrast to the prior art composite materials, where the inorganic carrier is solid / non-porous - which affects the increase in the degree of dispersity of the active phase and plays the role of separator of the carbon part and the catalytically active phase, the contact of which could lead to the gradual gasification of the adsorbent.

• - Umfassung von drei Arten von Substanzen mit unterschiedlichen Eigenschaften mit einem Verbundmaterial,
• - Erzielung der Multifunktionalität des Materials durch die entsprechend ausgewählten Inhaltsstoffe, was wie folgt vereinfacht dargestellt werden kann: Kern - Adsorption; anorganisches Oxid - Trägermittel und die Umhüllung vor der Deaktivierung (Vergasung) des Kerns; Aktivphase - Oxidation der adsorbierten VOCs;
• - Begrenzung der unvorteilhaften Deaktivierung des Kerns, der aus porösem Kohlenstoff gebildet ist, durch die oben beschriebene Modifizierung der Oberfläche;
• - Begrenzung der Durchdringung von Partikeln der katalytischen Phase in die Schicht des anorganischen Oxids, das das Trägermittel für die Aktivphase bildet, und damit die weitere Begrenzung der unvorteilhaften Deaktivierung von porösem Kohlenstoff, sowie die Erzielung einer hohen katalytischen Kapazität durch Exponieren der Katalysatorpartikeln;
• - Verwendung des Materials zur Eliminierung von flüchtigen organischen Verbindungen in katalytisch-adsorptiven Zyklen, die bei entsprechend niedrigen (20-100°C) und hohen Temperaturen geführt werden (über 150°C).
• - Möglichkeit, die Art und Menge von Oberflächenfunktionsgruppen der Kohlenstoffkerns zu kontrollieren, die eine selektive Adsorption von polaren und unpolaren flüchtigen organischen Verbindungen.

The advantages of the present invention over the solutions disclosed in the prior art are:

• - Encircling three types of substances with different properties with a composite material,
• Achieving the multifunctionality of the material by the appropriately selected ingredients, which can be simplified as follows: core adsorption; inorganic oxide - carrier and the coating before deactivation (gasification) of the core; Active phase - oxidation of adsorbed VOCs;
• Limiting the unfavorable deactivation of the core formed of porous carbon by the surface modification described above;
• Limiting the penetration of catalytic phase particles into the inorganic oxide layer forming the active phase carrier, thus further limiting the unfavorable deactivation of porous carbon, as well as achieving a high catalytic capacity by exposing the catalyst particles;
• - Use of the material for elimination of volatile organic compounds in catalytic-adsorptive cycles, which are conducted at correspondingly low (20-100 ° C) and high temperatures (above 150 ° C).
• - Possibility to control the type and amount of surface functional groups of the carbon nucleus that allow selective adsorption of polar and nonpolar volatile organic compounds.

The invention has been explained with reference to exemplary embodiments, which, however, are not directed to limiting the scope of protection. One of ordinary skill in the art will appreciate that it is possible to substitute the means recited in the embodiments to adapt the conditions of the method of obtaining material comprising alternative variant of the invention comprising the ingredients listed in the claims.

• 1 veranschaulicht die Isothermen der Adsorption-Desorption von Stickstoff für das Verbundmaterial MCM-48/CMK-1@ZrO₂ bevor und nach der Entfernung von dem Siliciumdioxid-Templat unter Verwendung von 1 M NaOH bei 25°C (Probe CMK-1@ZrO₂_1M_25°C) und 3 M NaOH bei 50°C (CMK-1@ZrO₂_3M_50°C).
• 2 veranschaulicht die Ergebnisse der durchgeführten Adsorptionstests, den die Kohlenstoffabdrucke unterzogen werden, die im Folge der Extraktion von einem strukturbildenden Templat mithilfe 5% HF und 1 M NaOH erhalten wurden.
• 3 veranschaulicht die Ergebnisse der katalytischen Tests von Materialien 1%Pt-CMK1@ZrO₂ (Ausführungsbeispiel 1) und Materialien 10%CuO-sC@ZrO₂ und 10%Co₃O₄-sC@ZrO₂ (Ausführungsbeispiel 2). Die Signaturen der Materialien werden im Folgenden im Abschnitt mit Ausführungsbeispielen entziffert.

In the following, the descriptions of the figures are shown, which are explained in detail in exemplary embodiments.

• 1 Figure ₃ illustrates the adsorption-desorption nitrogen isotherms for the composite MCM-48 / CMK-1 @ ZrO ₂ before and after removal from the silica template using 1 M NaOH at 25 ° C (sample CMK-1 @ ZrO ₂ _1M_25 ° C) and 3 M NaOH at 50 ° C (CMK-1 @ ZrO ₂ _3M_50 ° C).
• 2 illustrates the results of the adsorption tests performed on the carbon prints obtained as a result of extraction from a patterning template using 5% HF and 1 M NaOH.
• 3 Fig. 12 illustrates the results of the catalytic tests of materials 1% Pt-CMK1 @ ZrO ₂ (Embodiment 1) and materials 10% CuO-sC @ ZrO ₂ and 10% Co ₃ O ₄ -sC @ ZrO ₂ (Embodiment 2). The signatures of the materials are deciphered below in the section with exemplary embodiments.

Examples

• MCM-48/CMK-1@ZrO₂ - Kohlenstoff-Siliciumdioxid-Verbundstoff mit Kohlenkern mit Bezeichnung CMK-1, mit dem Siliciumdioxid vom Typ MCM-48 und mit einer Schicht des Zirkonoxids,
• CMK-1@ZrO₂ - Kohleabdruck CMK-1 mit der aufgebrachten Schicht des Zirkonoxids ZrO₂, nach der Entfernung von dem strukturbildenden Templat aus Verbundstoff MCM-48/CMK-1@ZrO₂ (Bezeichnung ohne Angabe von der Bedingungen für die Entfernung der Siliziumdioxid-Matrize allgemein verwendet).
• CMK-1@ZrO₂_1M_25°C - Kohleabdruck CMK-1 mit der aufgebrachten Schicht des Zirkondioxids ZrO₂, nach der Entfernung von dem strukturbildenden Templat bei einer Temperatur von 25°C unter Verwendung von 1 M NaOH.
• 10%Co₃O₄- sC@ZrO₂ - der auf Basis von sphärischem Siliciumdioxidgel erhaltene Kohleabdruck mit der aufgebrachten Schicht des Zirkonoxid ZrO₂ und abgeschiedener Aktivphase Co₃O₄ in einer Menge von 10 Gew.-% Co in Bezug auf das Gewicht des anorganischen Oxids (ZrO₂-Hülle).
• sC - der sphärische, auf Basis von dem handelsüblichen sphärischen Siliciumdioxidgel erhaltene Kohleabdruck.

In embodiments, the following designations have been used for specific materials:

• MCM-48 / CMK-1 @ ZrO ₂ - Carbon-silica composite with carbon nucleus designated CMK-1, with MCM-48 type silica and with a layer of zirconia,
• CMK-1 @ ZrO ₂ - carbon print CMK-1 with the applied layer of zirconia ZrO ₂ , after removal from the structure-forming template of composite MCM-48 / CMK-1 @ ZrO ₂ (designation without specifying the conditions for the removal of the Silica die generally used).
• CMK-1 @ ZrO ₂ _1M_25 ° C - carbon print CMK-1 with the applied layer of zirconia ZrO ₂ after removal from the patterning template at a temperature of 25 ° C using 1 M NaOH.
• 10% Co ₃ O ₄ - sC @ ZrO ₂ - the carbonaceous impression obtained on the basis of spherical silica gel with the coated layer of zirconium oxide ZrO ₂ and deposited active phase Co ₃ O ₄ in an amount of 10% by weight of Co by weight of the inorganic oxide (ZrO ₂ envelope).
• sC - the spherical carbon print obtained on the basis of the commercial spherical silica gel.

Other, analogical names are to be deciphered by the above-mentioned terms.

example 1

The following is the process for obtaining the composite material of the present invention.

Synthesis of Spherical Mesoporous Silica Material Type MCM-48

Into a round bottom flask of 500 mL volume was added 67.0 mL of distilled water, 105.0 mL of methanol (99.8% Aldrich), 30.0 mL of ammonia water (25% water solution, POCH), 16.0 mL of hexadecyltrimethylammonium chloride (water solution 25% Aldrich). The solution was stirred with a magnetic stirrer (400 rpm) at room temperature for 15 min. Subsequently, 15.0 mL of tetraethoxysilane (TEOS, 98%, Aldrich) was dropped in at a rate of about 2-3 drops per second with constant stirring. After dropping TEOS, stirring was continued for 2 hours. The resulting suspension was drained from the Buchner funnel and washed with distilled water (5 × 250 ml). The resulting product was dried overnight at a temperature of 90 ° C and then calcined in air at a temperature of 550 ° C for 6 hours with a temperature increase of 1 ° C / min. subjected.

Synthesis of MCM-48 silica-based spherical polymer-silica composite and its thermal modification

The polymer-silica composite was obtained by the solvent and precipitate-based polycondensation of furfuryl alcohol (FA) in an aqueous suspension of the silica support MCM-48. 100 ml of distilled water, 2.00 g of mesoporous silica and 2.5 g of furfuryl alcohol were placed in the round bottomed flask of 250 ml volume placed in the oil bath on the magnetic stirrer with the hot plate and fitted with a thermometer and reflux condenser. The resulting suspension was stirred for 30 min. (400 rpm) and then an acidic polycondensation catalyst (HCl, 35-38%, POCH) was added in an amount corresponding to the molar ratio FA: HCl = 1: 6. Subsequently, the reaction mixture was heated to boiling point and, with the continuation of the mixture, the polycondensation reaction was carried out for 6 hours. The product was drained from the Buchner funnel with elution with distilled water (3 × 100 ml) and dried overnight at a temperature of 90 ° C. The resulting polymer-silica composite was placed in a quartz pan and allowed to carbonize in a tube furnace using isothermal soaking conditions for 4 hours at a temperature of 850 ° C (temperature rise of 1 ° C / min) in a nitrogen stream (40 ° C) mL / min). As a result of the thermal modification, a carbon-silica composite was obtained which forms the core precursor of the final catalyst.

Application of ZrO ₂

The spherical carbon-silica composite was dispersed in the 100 g ethyl alcohol-containing round bottomed flask having a volume of 250 mL. The drum was then placed on the magnetic stirrer and heated to 30 ° C. 0.5 mL of nonionic aqueous solution of the surfactant Lutensol AO5 (3.76 wt.%) Was added. After one hour, 1.8 mL of zirconium butoxide (80 wt% in butanol) was condensed and the reaction was carried out for 15 hours. In the next step, the material obtained was centrifuged and washed several times with distilled water. The synthesized half-product was aged in water for complete hydrolysis of the substrate for 3 days, after which the preparation was centrifuged, dried and heated in an inert gas stream at 900 ° C. for 2 hours with a temperature rise of 2 ° C./min. be heated.

Removal of Carbon-Silica Composite Silicon with ZrO ₂ (MCM-48 / CMK-1 @ ZrO ₂ )

Extraction of the MCM-48 core was performed using a sodium base. For this purpose, the carbon-silica composite MCM-48 / CMK-1 @ ZrO _{2 was divided} into two equal portions and flooded with the NaOH solution in a concentration of 1 and 3 M, and then the assembly was heated to a temperature of 25 and heated to 50 ° C. After 24 hours, the precipitate was filtered off, washed to remove Na ⁺ cations exactly with distilled water and dried. The results confirm that the removal of the template can be realized in different conditions.

The results of etching the MCM-48 template with the NaOH solution in a concentration of 1 or 3 M at a temperature of respectively 25 or 50 ° C were described in Example 3.

Application of the active phase Pt with nanometric quantities

Pt nanoparticles were obtained by reduction of PtCl ₄ with NaOH in anhydrous solution of ethylene glycol. To this was dissolved 0.018 g of PtCl ₄ in a solution containing 0.016 g of NaOH in 5 mL of ethylene glycol. After 30 minutes, the solution was heated to a temperature of 160 ° C and held for a further 3 hours, then cooled to room temperature. The resulting Pt nanoparticles were applied to the surface of the inorganic shell with 1 g carbon support with applied zirconia CMK-1 @ ZrO ₂ . For this, the carrier was flooded with the resulting solution and left on the magnetic stirrer for 24 hours. Subsequently, the material was washed with distilled water and dried.

Example 2

The following is the process for obtaining the composite material of the present invention.

Synthesis of Spherical Mesoporous Carbon Material Based on Commercial Spherical Silica with 40-75 μm Particles.

To synthesize the spherical carbon materials, commercially available 40-75 μm spherical silica (Sigma-Aldrich) silica was used as a hard template. In the first step, a low pH sugar solution was prepared by dissolving 1.25 g of sucrose in 5.0 mL of water acidified with 0.14% concentrated sulfuric acid (VI). The previously dried (100 ° C, 1 h) silica gel was impregnated with sucrose solution by dry impregnation. The silica modified in this manner was heated in an air atmosphere, initially at a temperature of 100 ° C for 6 hours, and then for 6 hours at a temperature of 160 ° C. The ready-to-use preparation of the brown color was gently ground in a porcelain mortar and subjected to the impregnation process again. The resulting black material was stirred in a porcelain mortar and placed in a tube furnace, and heated for 4 hours at a temperature of 850 ° C with temperature rise of 1 ° C / min. in nitrogen stream (40 mL / min) to produce a carbon-silica composite. From the synthesized carbon-silica composite, the silica template was removed by washing twice with 5% hydrofluoric acid solution at room temperature using 30 mL of HF solution per 1 g of the composite. The carbon material was isolated from the solution by filtering on a fluted filter and rinsing with water (3x100 mL) and ethanol (1x100 mL) to remove excess water. The obtained carbon print was then dried at a temperature of 80 ° C for 12 h.

Application of ZrO ₂

Spherical porous sC-carbon (0.5 g) was dispersed in 5 mL of anhydrous ethanol. The suspension was placed in a round bottom flask and 0.1 mL of distilled water and Brij 30 surfactant (0.1 mL) were added. The flask is placed on a magnetic stirrer and its contents are stirred for 30 minutes. Then, 0.2 mL of zirconium butoxide (80 wt% in butanolate) was dropped. The reaction of the hydrolysis was conducted for 8 hours. The resulting material was centrifuged and washed several times with distilled water. The isolated product was aged in water for 12 hours at room temperature to ensure complete condensation of the ZrO ₂ precursor. After this time, the preparation was dried for 24 hours at 75 ° C and the inert gas stream for 2 hours at 850 ° C with a temperature increase of 2 ° C / min. be heated.

Apply the active phase using dry impregnation

In the first step, the sorption capacity of the carrier of the catalytically active element (in this case sC @ ZrO ₂ ) with respect to water was determined. Using an automatic pipette, small portions (20 μL each) of distilled water were dripped in until the vitrification effect occurred. The sorbent capacity of the vehicle was 700 μL / g. Based on this value, samples of 1 g of the carrier were impregnated with the volume of the solutions with concentrations of salts of a particular metal (cupric nitrate (V) or cobalt (II) nitrate (V) required for the introduction of 2 , 5, 5.0, 7.5, 10.0 and 15.0 wt.% Of Cu and Co. are required with respect to the mass of the zirconia, and after impregnation, the materials were dried and then at 500 ° C in an air atmosphere with a temperature rise of 5 ° C / min. and holding the preset temperature for 3 hours calcined.

Example 3

Comparison of the Porosity of Materials of the Invention Obtained by a Method Other Than the Methods of Example 1 and 2 for Removal of the Silica Template.

The process of structural evolution of core-shell materials obtained according to Example 1 was investigated with low-temperature nitrogen adsorption. The chemical composition of the obtained preparations was determined by the XRF method. The low temperature sorption of nitrogen was measured with ASAP 2020 Sorptomat (Micromeritics) with about 200 mg sample. Before the measurement, the materials were degassed at a temperature of 150 ° C for 6 hours. Chemical composition analyzes were performed in the Thermo Scientific EDXRF Quant'x Arl spectrometer equipped with a Rh source. Each time, about 200 mg of the sample placed in a holder on a polypropylene film was used.

The thermal stability of the fabricated materials was investigated using the TA Instruments SDT Q600 thermogravimeter. The experiments were carried out for an approximately 10 g sample in the air stream (100 mL / min) in the range of 30-100 ° C with a temperature increase of 20 ° C / min. carried out.

1 Figure 4 shows the adsorption-desorption isotherms of nitrogen for the composite MCM-48 / CMK-1 @ ZrO ₂ and after removal from the silica template using 1 M NaOH at 25 ° C (sample CMK-1 @ ZrO ₂ _1M_25 ° C) and 3 M NaOH at 50 ° C (CMK-1 @ ZrO ₂ _3M_50 ° C).

Low temperature nitrogen sorption isotherms and texture parameters calculated therefrom illustrate the influence of the guide conditions of extraction from the patterning template (MCM-48) on the porosity of the resulting materials. The starting material MCM-48 / CMK-1 @ ZrO ₂ has a high content of silicon dioxide, ie 48.3% (XRF investigations). The extraction of SiO ₂ at 25 ° C leads to its considerable elimination and thus causes the opening of the porous structure in the examined preparation. Increasing the reaction temperature of the process to 50 ° C and the concentration of NaOH solution to 3 M led to further increase in porosity. This effect is observed in the course of the isotherms of N ₂ adsorption desorption by a significant increase in the volume adsorbed at low relative pressure p / po, which is related to the occurrence of micro- and mesopores. The values of Vmicro and Vmeso shown in Table 1 confirm this thesis. The formation of new pores affects the S _BET specific surface area, which has increased from 306 to 514 m ² / g for the material with the most successfully removed SiO ₂ core.

In Table 1, the determined texture parameters and the chemical composition of the materials were collected depending on the conditions of the SiO ₂ core extraction. Table 1 Results of physico-chemical characterization of selected materials sample TG XRF Low temperature sorption of N ₂ Organ rather salary [%] SiO 2 [%] ZrO 2 [%] S _BET ^a [m ² / g] Vges amt ^b [cm ³ / g] Vmikr o ^c [cm ³ / g] Vmes o ^d [cm ³ / g] Vmak ro ^e [cm ³ / g] MCM-48 / CMK-1 @ ZrO ₂ 25.0 48.3 26.7 306 0.24 0.06 0.13 0.06 CMK-1 @ ZrO ₂ _1M_25 ° C 50.4 13.3 36.3 421 0.60 0.06 0.40 0.14 CMK-1 @ ZrO _{2_} 3M_50 ° C 53.4 8.5 38.1 514 0.61 0.10 0.40 0.11 ^a S _BET - specific surface area (BET) ^b V _total - total pore volume (one-point method) ^c V _micro - micropore volume (t-plot method) ^d V _meso - mesopore volume (BJH method) ^e V _macro - macropore volume ((V _total - (V _meso + V _micro ))

Example 4

Comparison of the adsorption properties of carbon cores of the composite.

Synthesis of spherical carbon prints based on wide-pore silica gel (particle size 40-75 μm and 75-200 μm) and the influence of the method for removing the structure-forming template on the adsorption properties.

5 g of spherical silica gel was added to the porcelain crucible, dry-impregnated with concentrated sulfuric acid (VI) and then heated in the oven for 3 hours at a temperature of 150 ° C. After cooling, the mixture was placed in a beaker containing about 200 mL of distilled water and subjected to sedimentation under static conditions. The remaining clear solution was decanted, the precipitate dispersed in a new portion of distilled water and filtered and washed with distilled water until complete neutralization of the filtrate, then dried for 2 hours at a temperature of 120 ° C. Furfuryl alcohol, as a carbon precursor, was incorporated into the pore system of sulfonated silica by dry impregnation, and then polycondensation was conducted under static conditions in a closed container at a temperature of 100 ° C for 24 hours. The resulting polymer-silica nanocomposite was heated in nitrogen flow (40 mL / min) at a temperature of 850 ° C for 4 hours with a temperature rise of 1 ° C / min. carbonized.

The material obtained before the etching of silicon dioxide was divided into two parts, which differed in the manner of removing silica. The inorganic template of the first part was etched with a 5% water solution of hydrofluoric acid. For this purpose, the material was dispersed in acid in an amount of 30 mL / g and left for 1 hour under static conditions. The second part was subjected to etching with the 1M NaOH solution. As in the previous case, a solution of 30 mL / g was used. The etching was carried out twice under static conditions for 24 hours. The resulting carbon prints were then filtered on a pleated filter and washed out to neutralize the filtrate with distilled water followed by ethanol (2 x 20 mL) and dried overnight at a temperature of 90 ° C.

The resulting materials were designated s-CR_40-75_z and s-CR_75-200_z where: z denotes the etchant (HF or NaOH).

2 Figure 2 illustrates the results of the adsorption tests performed on the carbon prints obtained as a result of extraction from a patterning template using 5% HF and 1 M NaOH.

The results obtained confirm that the carbon prints forming the core of the composite material described in the invention are characterized by high sorption capacities compared to all VOC representatives surveyed. It has been demonstrated that an important parameter affecting the hydrophilicity of the carbon material surface is the selection of the agent that etches the silica die. The use of sodium base solution makes it possible to obtain a material with high hydrophilicity, which has a similar affinity to both polar and non-polar adsorbates. Removal of the template with hydrofluoric acid results in obtaining a material with a lower content of superficial oxygen groups, which leads to a significant decrease in its hydrophilicity and thus to a significantly lower affinity for polar adsorbates. Also, the calculated sorption capacity with respect to toluene vapors decreases, whereas with n-heptane a slight increase was noted.

Example 5

Comparison of Adsorption and Desorption Characteristics of Carbon Core, ZrO ₂ Carbon Core and Carbon ZrO ₂ and Pt Shell in relation to Toluene Vapor.

The adsorption properties of materials were investigated by dynamic adsorption-desorption of toluene vapors with the detector in the form of a QMS mass spectrometer. The carrier gas stream saturated with toluene vapor (nitrogen or air, 100 ml / min) (toluene content in the carrier gas equal to 0.1% by volume) was fed to a flow reactor with a stationary adsorption bed (50 mg). The reactor was maintained at a temperature of 68 ° C in which the toluene vapor pressure p / p ₀ = 0.25. The sorption was carried out for 1.5 hours after opening the valve and then the system was switched to desorption mode (the flow of pure carrier gas was 100 mL / min). Table 2 Dynamic Adsorption and Desorption Test Results of Toluene Vapors - Physically Adsorbed Forms sample Imprint CMK-1 CMK-1 / ZrO ₂ Pt-CMK-1 / ZrO ₂ capacity [Mg / g] Carrier gas - nitrogen 48.9 38.6 42.4 Carrier gas - air - 27.1 27.3 TABLE 3 Results of dynamic adsorption and desorption tests of toluene vapors - total amount of adsorbed toluene sample Imprint CMK-1 CMK-1 / ZrO ₂ Pt-CMK-1 / ZrO ₂ capacity [Mg / g] Carrier gas - nitrogen 168.9 158.8 103.8 Carrier gas - air - 51.7 75.8

The results of the experiments confirmed the high sorption capacity of the materials according to the invention. Although the modification of the carbon surface reduced the adsorption capacity of the materials relative to the carbon precursor, the ZrO ₂ shell increased the thermal stability of the carbon core under an oxidizing atmosphere compared to the exemplary mesoporous carbon CMK-1. The ZrO ₂ shell isolates the carbon core of the oxidizing atmosphere catalyst in which the catalytic VOC post combustion process is carried out and protects it from combustion. Application of the active phase caused the increase in sorption capacity to CMK-1 / ZrO ₂ .

Example 6

Evaluation of the catalytic activity of the materials according to the invention.

The change in the catalytic activity of the materials 1% Pt-CMK1 @ ZrO ₂ (Example 1) and materials 10% CuO-sC @ ZrO ₂ and 10% Co ₃ O ₄ -sC @ ZrO ₂ (Example 2) as a function of temperature was in 3 shown. The catalytic tests were carried out with a flow-through system equipped with a quartz microreactor in the air stream (100 mL / min, toluene concentration 1000 ppm). To detect the amount of substrates / reaction products, a mass spectrometer equipped with a quadrupole mass detector was used. The experiment was carried out in a temperature range of 50-500 ° C, with a continuous increase of 1 ° C / min. for a sample of 100 mg. Prior to the experiment, the sample was degassed for 30 minutes in an inert gas stream (50 mL / min) at 200 ° C.

The results of the test confirmed a high catalytic activity of the developed materials. The total oxidation of the adsorbed toluene vapors was at 210 ° C for 1% Pt-CMK1 @ ZrZrO ₂ material and 400 ° C for samples containing CuO or Co ₃ O ₄ as the active phase. Such a low temperature of toluene oxidation in combination with a high sorptive capacity of the carbon nucleus indicates its potential use as bifunctional materials in the process for the adsorption-catalytic elimination of volatile organic compounds.

The embodiments illustrate the method of obtaining the composite materials of the invention for the selected but representative ingredients that make up the composite. For the expert, it is understood that the expert will use other catalytically active substances instead of platinum or CuO or Co ₃ O ₄ based on the common knowledge and available literature, using the example of the use of platinum or CuO or Co ₃ O ₄ . The collection of elements and oxides in the group Pt, Pd, Rh, Re, Ir, Au, Co ₃ O ₄ , CuO, Mn ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , CeO ₂ , NiO, ZnO, Fe ₂ O ₃ , which is indicated in claim 1 as an element of the essence of the invention, is therefore reflected in a typical selection of catalytically active substances that would be encountered by an expert in this field. One skilled in the art would also adapt the parameters for obtaining a composite with each of the listed components of the catalytically active phase in consideration of routine procedures and remain within the scope of the present invention.

Similar interpretation is given for inorganic oxides selected from the group of zirconia, titania, alumina, ceria. These oxides are similar in structure and chemical function and would be considered appropriate by one skilled in the art to practice the invention if, for one of them, the invention could be practiced, as confirmed in the examples.

Notwithstanding, it should be emphasized that the use of equivalent ingredients of the composite, which is within the scope of protection, does not imply that the composite itself, the method of obtaining it, or its use, should be taken for granted. The combination of the relevant components in an appropriate manner and the use of special parameters of the process steps resulted in an unexpected result in the form of an invention, which is described in the description and exemplified.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 16069856 A1 [0009]
• WO 09/15434 A1 [0010]
• US 2015057149A [0011]
• CN 103480369 B [0012]

Claims (27)

Composite material in the form of solid particles having a core-shell active phase structure comprising a core of adsorption material, at least one inorganic oxide and particles of the catalytically active phase, characterized in that: the adsorption material is a porous carbon, the inorganic oxide, that the core shell and the carrier agent is the catalytically active phase selected from the group comprising zirconium oxide, titanium oxide, alumina, cerium oxide, - the catalytically active phase consists of nanoparticles and their agglomerates based on metals or metal oxides consisting of the Pt, Pd , Rh, Re, Ir, Au, Co ₃ O ₄ , CuO, Mn ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , CeO ₂ , NiO, ZnO, Fe ₂ O ₃ or mixtures thereof. Composite according to Claim 1 , characterized in that the solid particles are spherical. Composite according to Claim 1 , characterized in that the solid particles have a diameter in the range of 50 nm to 500 microns. Composite according to Claim 1 , characterized in that the carbon core is a mesoporous carbon material having the specific surface area of the range 200-2000 m ² / g and the pore volume in the range of 0.3 to 2.5 cm ³ / g. Composite according to Claim 1 or 4 , characterized in that the core surface of porous carbon has a content of oxygen functional groups in the range up to 15 wt .-%. Composite according to Claim 1 , characterized in that the thickness of the shell of the inorganic oxide is in the range of 10-100 nm. Composite according to Claim 1 , characterized in that the inorganic oxide is porous. Composite according to Claim 1 , characterized in that the catalytically active phase is composed of metals or the metal oxides applied to the shell of the inorganic oxide and the shell itself. Composite according to Claim 8 , characterized in that metals or metal oxides which form the active phase are selected from the group comprising Pt, CuO, Co ₃ O ₄ . Composite according to Claim 1 , characterized in that the nanoparticles of the catalytically active phase are deposited on the surface of the inorganic oxide without contact with the carbon nucleus. Composite according to Claim 1 , characterized in that the amount of catalytically active metal in the final material is from 0.1 to 25.0% with respect to the total mass of the oxygen shell. Method for obtaining the im Claim 1 composite material comprising the following steps: a) obtaining porous carbon material, b) applying the oxygen sheath to the core of porous carbon material, c) depositing the particles of the catalytically active phase onto the oxygen sheath. The method for obtaining the material according to Claim 12 characterized in that step a) is carried out by shaping the rigid silica templates where the carbon precursor is introduced into the silica matrix by impregnation, vapor deposition or in situ polymerization. The method for obtaining the material according to Claim 13 characterized in that the polymers obtained by in situ polymerization of monomers selected from the group consisting of furfuryl alcohol, phenol-formaldehyde mixture and acrylonitrile are carbon precursors. The method for obtaining the material according to Claim 13 , characterized in that the sugars selected from the group: sucrose, glucose and xylose are the carbon precursors. The method for obtaining the material according to Claim 13 characterized in that the silica templates are based on silica gel or mesoporous silica materials of the SBA-15, SBA-16, MCM-41 and MCM-48 spherical particle form. The method for obtaining the material according to Claim 13 characterized in that the obtaining of porous carbon material is to introduce the carbon precursor into the pore system of the spherical silica material to recover a polymer-silica composite which is subsequently carbonized at a temperature in the range of 600-1000 ° C under an inert gas atmosphere (argon, nitrogen, helium), and then the silica is removed from the carbon-silica material by etching with acid or alkaline solution. The composite according to Claim 17 , characterized in that the etching of the silica from the carbon-silica composite results in the modification of its surface which consists in the generation of oxygen functional groups. The composite according to Claim 18 , characterized in that the etching is carried out using NaOH having a concentration in the range of 1-5 M or the HF solution having a concentration in the range of 1 to 10% at a temperature in the range 25-90 ° C to achieve a correspondingly hydrophilic or hydrophobic character of the core surface. The method for obtaining the material according to Claim 17 , characterized in that the removal of silica is carried out before or after the deposition of the shell of the inorganic oxide. The method for obtaining the material according to Claim 12 , characterized in that the oxide shell in step b) is applied by hydrolysis and polycondensation of a metal alkoxide. The method for obtaining the material according to Claim 21 , characterized in that the reaction is conducted in anhydrous alcohol solution in the presence of a surfactant. The method for obtaining the material according to Claim 12 characterized in that after step b) the material is dried and carbonated for 1 to 48 hours at a temperature in the range of 600-1000 ° C under an inert gas atmosphere, the temperature being at a rate of 0.1 to 50 ° C / min. is increased. The method for obtaining a composite material according to Claim 12 , characterized in that the nanoparticles of the catalytically active phase in step c) are applied to the layer of inorganic oxide by the impregnation process from a solution of a readily soluble compound of a selected metal. The use of the im Claim 1 described composite material for the elimination of the volatile organic compounds by adsorption in the core formed of porous carbon and their subsequent catalytic oxidation by the present in the shell catalytically active phase. The use of the im Claim 25 described composite material, characterized in that the adsorption of volatile organic compounds takes place at a temperature in the range of 20-100 ° C, and the catalytic afterburning in the temperature range above 150 ° C. The use of the im Claim 23 described composite material, characterized in that the volatile organic compounds are selected from the group comprising aliphatic aromatic hydrocarbons, alcohols, ketones, aldehydes and esters.

Images