Pub Date : 2023-01-16DOI: 10.18412/1816-0387-2023-1-6-14
V. Doronin, T. V. Bobkova, T. P. Sorokina, O. Potapenko, A. S. Yurtaeva, N. N. Leontieva, T. Gulyaeva
The amorphous aluminosilicate – alumina systems were examined using various physicochemical methods, including the analysis of 27Al NMR spectra of solid samples, estimation of the catalyst acidity by temperature-programmed desorption of ammonia, investigation of the sample structure by X-ray diffraction analysis, and thermogravimetric analysis of the samples. A study on the catalytic properties of the samples upon cracking on the model feedstock n-dodecane in a mixture with 2-methylthiophene revealed that conversion of the feedstock increases in the series: 100 % Al2O3 (AH) > 70 % Al-Si + 30 % Al2O3 (AH) > 30 % Al-Si + 70 % Al2O3 (AH) > 100 % Al-Si (AH – aluminum hydroxide obtained by sulfate method; Al-Si – amorphous aluminosilicate). An increase in the calcination temperature of the samples from 500 to 700 °C decreases the conversion of the feedstock. The growing contribution of hydrogen transfer reactions leads to an increase in the formation selectivity of hydrogen sulfide and a decrease in the content of sulfur compounds in the liquid products.
{"title":"Structural and Catalytic Properties of the Binary Systems Alumina – Amorphous Aluminosilicate","authors":"V. Doronin, T. V. Bobkova, T. P. Sorokina, O. Potapenko, A. S. Yurtaeva, N. N. Leontieva, T. Gulyaeva","doi":"10.18412/1816-0387-2023-1-6-14","DOIUrl":"https://doi.org/10.18412/1816-0387-2023-1-6-14","url":null,"abstract":"The amorphous aluminosilicate – alumina systems were examined using various physicochemical methods, including the analysis of 27Al NMR spectra of solid samples, estimation of the catalyst acidity by temperature-programmed desorption of ammonia, investigation of the sample structure by X-ray diffraction analysis, and thermogravimetric analysis of the samples. A study on the catalytic properties of the samples upon cracking on the model feedstock n-dodecane in a mixture with 2-methylthiophene revealed that conversion of the feedstock increases in the series: 100 % Al2O3 (AH) > 70 % Al-Si + 30 % Al2O3 (AH) > 30 % Al-Si + 70 % Al2O3 (AH) > 100 % Al-Si (AH – aluminum hydroxide obtained by sulfate method; Al-Si – amorphous aluminosilicate). An increase in the calcination temperature of the samples from 500 to 700 °C decreases the conversion of the feedstock. The growing contribution of hydrogen transfer reactions leads to an increase in the formation selectivity of hydrogen sulfide and a decrease in the content of sulfur compounds in the liquid products.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83828012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-16DOI: 10.18412/1816-0387-2023-1-29-36
E. Yakovleva, Mural Nurbol, G. A. Bukhtiyarova
Capillary chromatographic columns with different stationary phases were studied in order to compare their ability to estimate purity of isopropyl alcohol obtained by hydrogenation of acetone. The study was performed with the columns based on polyethylene glycol 20 M terminated with 2-nitroterephthalic acid (PEG20M/FFAP); poly(1-trimethylsilyl-1-propyne) (PTMSP032); and trifluoropropyl (25 %) methyl silicone elastomer (SKTFT 50X). A comparison of the measurement time, asymmetry factors (As) for components of the mixtures, and resolution (Rs) for the pairs of compounds acetone/isopropanol and isopropanol/internal standard gave grounds to choose a capillary column PEG20M/FFAP. A technique was developed for measuring the weight fractions of acetone and isopropanol using the method of internal standard in the gas phase. n-Butanol served as the internal standard. The detection limit was found to be 1.45 for acetone, 1.43 for isopropanol, and 1.28·10–12 g/s for n-butanol. Relative standard deviation (the recurrence factor) did not exceed 4.3 % at a confidence level P = 0.95.
{"title":"Development of the Method and Technique to Analyze Acetone Hydrogenation Products by Gas Chromatography","authors":"E. Yakovleva, Mural Nurbol, G. A. Bukhtiyarova","doi":"10.18412/1816-0387-2023-1-29-36","DOIUrl":"https://doi.org/10.18412/1816-0387-2023-1-29-36","url":null,"abstract":"Capillary chromatographic columns with different stationary phases were studied in order to compare their ability to estimate purity of isopropyl alcohol obtained by hydrogenation of acetone. The study was performed with the columns based on polyethylene glycol 20 M terminated with 2-nitroterephthalic acid (PEG20M/FFAP); poly(1-trimethylsilyl-1-propyne) (PTMSP032); and trifluoropropyl (25 %) methyl silicone elastomer (SKTFT 50X). A comparison of the measurement time, asymmetry factors (As) for components of the mixtures, and resolution (Rs) for the pairs of compounds acetone/isopropanol and isopropanol/internal standard gave grounds to choose a capillary column PEG20M/FFAP. A technique was developed for measuring the weight fractions of acetone and isopropanol using the method of internal standard in the gas phase. n-Butanol served as the internal standard. The detection limit was found to be 1.45 for acetone, 1.43 for isopropanol, and 1.28·10–12 g/s for n-butanol. Relative standard deviation (the recurrence factor) did not exceed 4.3 % at a confidence level P = 0.95.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86191039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.18412/1816-0387-2022-6-41-50
O. A. Knyazheva, O. N. Baklanova, E. A. Buluchevskiy, A. Arbuzov, M. V. Trenikhin, Т. Р. Karpova, M. Moiseenko, N. N. Leontieva, A. V. Lavrenov
The solid-phase synthesis of model aluminum-molybdenum (Al-Mo) and aluminum-nickel-molybdenum (Al-Ni-Mo) compositions constituting the catalysts for metathesis of propylene was carried out under mechanical action. The structure of model Al-Mo and Al-Ni-Mo compositions was studied using X-ray diffraction analysis, high-resolution transmission electron microscopy, infrared spectroscopy, and diffuse reflectance electron spectroscopy (UV-vis DRS). The latter method revealed the presence of isolated monomeric and oligomeric molybdate compounds in the model Al-Ni-Mo compositions. Granulated catalysts for metathesis were obtained by molding the model Al-Mo and Al-Ni-Mo compositions with aluminum hydroxide followed by calcination. Most active in the metathesis of propylene was the aluminum-molybdenum catalyst containing 2.6 wt.% Ni, 13.0 wt.% Mo and 32.7 wt.% Al. At the process temperature of 200 °С, pressure 0.1 MPa, and weight space velocity of propylene 1 h–1, the conversion of propylene on this catalyst reached 33.7 %, which makes the catalyst promising for practical application. Therewith, the weight fraction of ethylene in the reaction products was 17.5 %, and butenes – 71.3 %.
{"title":"Solid-Phase Synthesis of Nickel-Molybdenum Catalysts for Metathesis of Propylene under Mechanical Action","authors":"O. A. Knyazheva, O. N. Baklanova, E. A. Buluchevskiy, A. Arbuzov, M. V. Trenikhin, Т. Р. Karpova, M. Moiseenko, N. N. Leontieva, A. V. Lavrenov","doi":"10.18412/1816-0387-2022-6-41-50","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-6-41-50","url":null,"abstract":"The solid-phase synthesis of model aluminum-molybdenum (Al-Mo) and aluminum-nickel-molybdenum (Al-Ni-Mo) compositions constituting the catalysts for metathesis of propylene was carried out under mechanical action. The structure of model Al-Mo and Al-Ni-Mo compositions was studied using X-ray diffraction analysis, high-resolution transmission electron microscopy, infrared spectroscopy, and diffuse reflectance electron spectroscopy (UV-vis DRS). The latter method revealed the presence of isolated monomeric and oligomeric molybdate compounds in the model Al-Ni-Mo compositions. Granulated catalysts for metathesis were obtained by molding the model Al-Mo and Al-Ni-Mo compositions with aluminum hydroxide followed by calcination. Most active in the metathesis of propylene was the aluminum-molybdenum catalyst containing 2.6 wt.% Ni, 13.0 wt.% Mo and 32.7 wt.% Al. At the process temperature of 200 °С, pressure 0.1 MPa, and weight space velocity of propylene 1 h–1, the conversion of propylene on this catalyst reached 33.7 %, which makes the catalyst promising for practical application. Therewith, the weight fraction of ethylene in the reaction products was 17.5 %, and butenes – 71.3 %.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77953454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.18412/1816-0387-2022-6-51-67
D. A. Shlyapin, D. V. Glyzdova, T. Afonasenko, V. Temerev, A. V. Lavrenov
The effect of adsorption of the reaction medium components on selective hydrogenation of acetylene to ethylene under the action of supported palladium catalysts is considered. The role of interstitial solid solutions of carbon and hydrogen in palladium, which are formed upon contact of the catalyst with the reaction medium, in the mass-transfer processes between surface and subsurface layer of the active component is revealed. The ratio of activation barriers for ethylene desorption/adsorption processes, which determines the selectivity of acetylene hydrogenation, can change in dependence on the structure of palladium nanoparticles and its electronic state. Therewith, changes in the electronic state affect the energy of activated desorption of ethylene from palladium particles, and their structural features determine the energy of activated adsorption and the subsequent hydrogenation of ethylene to ethane.
{"title":"The Role of Interstitial Solid Solutions in the Formation of Active Component in Supported Palladium Catalysts for Selective Hydrogenation of Acetylene to Ethylene","authors":"D. A. Shlyapin, D. V. Glyzdova, T. Afonasenko, V. Temerev, A. V. Lavrenov","doi":"10.18412/1816-0387-2022-6-51-67","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-6-51-67","url":null,"abstract":"The effect of adsorption of the reaction medium components on selective hydrogenation of acetylene to ethylene under the action of supported palladium catalysts is considered. The role of interstitial solid solutions of carbon and hydrogen in palladium, which are formed upon contact of the catalyst with the reaction medium, in the mass-transfer processes between surface and subsurface layer of the active component is revealed. The ratio of activation barriers for ethylene desorption/adsorption processes, which determines the selectivity of acetylene hydrogenation, can change in dependence on the structure of palladium nanoparticles and its electronic state. Therewith, changes in the electronic state affect the energy of activated desorption of ethylene from palladium particles, and their structural features determine the energy of activated adsorption and the subsequent hydrogenation of ethylene to ethane.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84568153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.18412/1816-0387-2022-6-68-77
A. A. Buzaev, A. Rogacheva, T. Larina, E. V. Dokuchits, O. Khalipova, V. V. Zharkova
Two samples of TiO2 /Cr2O3 composites were synthesized as spherical grains by stepwise thermal treatment of ion-exchange resins, which were preliminarily saturated with chromium cations Cr3+ and dichromate anions Cr2O7 2– and covered with a film-forming solution of titania. The modes of calcination were based on thermal analysis and determined by the type of ion-exchange resin chosen as a template. The obtained composites consist mostly of the α-Cr2O3 phase, while the content of the TiO2 phase does not exceed 4 %. The composites retain the spherical grain shape of the initial ion-exchange resins with the size from 370 to 660 μm. Grains of the sample based on cationite, which adsorbs Cr3+ ions, have a pore structure with swells and voids. Grains of the sample based on anionite have fractures and cracks over the entire surface due to nonuniform distribution of adsorbed Cr2O72– anions in the initial anionite. The composites exhibit the catalytic activity in the complete oxidation of p-xylene. The sample based on cationite is more active. This may be related to a smaller accessible specific surface area of titania in the anionite-based sample due to formation of the Ti3+ solid solution in α-Cr2O3.
{"title":"Spherical TiO2 /Cr2O3 Composites Synthesized Using Ion-Exchange Resins as a Template","authors":"A. A. Buzaev, A. Rogacheva, T. Larina, E. V. Dokuchits, O. Khalipova, V. V. Zharkova","doi":"10.18412/1816-0387-2022-6-68-77","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-6-68-77","url":null,"abstract":"Two samples of TiO2 /Cr2O3 composites were synthesized as spherical grains by stepwise thermal treatment of ion-exchange resins, which were preliminarily saturated with chromium cations Cr3+ and dichromate anions Cr2O7 2– and covered with a film-forming solution of titania. The modes of calcination were based on thermal analysis and determined by the type of ion-exchange resin chosen as a template. The obtained composites consist mostly of the α-Cr2O3 phase, while the content of the TiO2 phase does not exceed 4 %. The composites retain the spherical grain shape of the initial ion-exchange resins with the size from 370 to 660 μm. Grains of the sample based on cationite, which adsorbs Cr3+ ions, have a pore structure with swells and voids. Grains of the sample based on anionite have fractures and cracks over the entire surface due to nonuniform distribution of adsorbed Cr2O72– anions in the initial anionite. The composites exhibit the catalytic activity in the complete oxidation of p-xylene. The sample based on cationite is more active. This may be related to a smaller accessible specific surface area of titania in the anionite-based sample due to formation of the Ti3+ solid solution in α-Cr2O3.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80703632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.18412/1816-0387-2022-6-30-40
M. Smolikov, V. Shkurenok, L. I. Bikmetova, N. N. Leontieva, A. V. Lavrenov
Isomerization of heptane and hexane and their mixtures in the presence of Pt/WO3-ZrO2 catalysts with the tungsten oxide content of 10–35 wt.% was studied. The best characteristics of isomerization of the С6–С7 alkanes mixture were observed on the catalysts with the WO3 content of 15–20 wt.%. According to ammonia thermodesorption data, the number of acid sites typically increases in this range of tungsten oxide content; according to IR spectroscopy of adsorbed CO, this occurs mostly with an increase in the number of Broensted acid sites.
{"title":"Simultaneous Isomerization of Hexane and Heptane in the Presence of Pt-Containing Tungstated Zirconia Catalysts","authors":"M. Smolikov, V. Shkurenok, L. I. Bikmetova, N. N. Leontieva, A. V. Lavrenov","doi":"10.18412/1816-0387-2022-6-30-40","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-6-30-40","url":null,"abstract":"Isomerization of heptane and hexane and their mixtures in the presence of Pt/WO3-ZrO2 catalysts with the tungsten oxide content of 10–35 wt.% was studied. The best characteristics of isomerization of the С6–С7 alkanes mixture were observed on the catalysts with the WO3 content of 15–20 wt.%. According to ammonia thermodesorption data, the number of acid sites typically increases in this range of tungsten oxide content; according to IR spectroscopy of adsorbed CO, this occurs mostly with an increase in the number of Broensted acid sites.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84596627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.18412/1816-0387-2022-6-6-15
G. Mamontov, E. Evdokimova, A. S. Savelyeva, A. Zubkov, N. Mikheeva, I. Mazov, A. Knyazev
Silica gels are the porous materials widely employed in both the industry and housekeeping. Domestic manufacturers produce bead and powder silica gels; however, some application fields of silica gels completely depend on the import. So it is necessary to develop technologies for their production, the introduction of which would allow replacing the imported silica gels. The paper describes methods for improving the properties of bead silica gels and new approaches to the production of powder silica gels and silica gels with the ordered pore structure. It was proposed to use inexpensive feedstock for their preparation, particularly, industrial wastes from the production of alumina – Si-stoff, and the natural material – diatomite. By controlling the parameters of deposition and formation of the silica structure it is possible to obtain silica gels with a wide range of pore structure characteristics, which could be used in various application fields.
{"title":"Silica Gel as a Sorbent and Catalyst Support: the Improvement of Technologies and the Search for Alternative Production Routes","authors":"G. Mamontov, E. Evdokimova, A. S. Savelyeva, A. Zubkov, N. Mikheeva, I. Mazov, A. Knyazev","doi":"10.18412/1816-0387-2022-6-6-15","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-6-6-15","url":null,"abstract":"Silica gels are the porous materials widely employed in both the industry and housekeeping. Domestic manufacturers produce bead and powder silica gels; however, some application fields of silica gels completely depend on the import. So it is necessary to develop technologies for their production, the introduction of which would allow replacing the imported silica gels. The paper describes methods for improving the properties of bead silica gels and new approaches to the production of powder silica gels and silica gels with the ordered pore structure. It was proposed to use inexpensive feedstock for their preparation, particularly, industrial wastes from the production of alumina – Si-stoff, and the natural material – diatomite. By controlling the parameters of deposition and formation of the silica structure it is possible to obtain silica gels with a wide range of pore structure characteristics, which could be used in various application fields.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83696228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.18412/1816-0387-2022-6-16-29
A. Gorshkov, L. V. Sineva, K. Gryaznov, E. Asalieva, V. Mordkovich
Endurance tests of the zeolite-containing cobalt catalyst for the Fischer – Tropsch synthesis were carried out in reactor tubes of the size comparable with those used in industrial reactors. During the tests (3000 h), the catalyst activity decreased by 13 %. Deactivation of the zeolite-containing cobalt catalyst was shown to occur due to agglomeration of cobalt clusters and formation of amorphous carbon on their surface. A method of decreasing the catalyst deactivation rate and two methods of the catalyst regeneration were proposed. The method of redox regeneration of zeolite-containing cobalt catalysts allows restoring 98 % of their initial activity.
{"title":"Features of Deactivation and Regeneration of the Zeolite-Containing Cobalt Catalyst in a Fischer – Tropsch Synthesis Reactor","authors":"A. Gorshkov, L. V. Sineva, K. Gryaznov, E. Asalieva, V. Mordkovich","doi":"10.18412/1816-0387-2022-6-16-29","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-6-16-29","url":null,"abstract":"Endurance tests of the zeolite-containing cobalt catalyst for the Fischer – Tropsch synthesis were carried out in reactor tubes of the size comparable with those used in industrial reactors. During the tests (3000 h), the catalyst activity decreased by 13 %. Deactivation of the zeolite-containing cobalt catalyst was shown to occur due to agglomeration of cobalt clusters and formation of amorphous carbon on their surface. A method of decreasing the catalyst deactivation rate and two methods of the catalyst regeneration were proposed. The method of redox regeneration of zeolite-containing cobalt catalysts allows restoring 98 % of their initial activity.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73269769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-29DOI: 10.18412/1816-0387-2022-5-27-39
M. A. Matsko, N. V. Semikolenova, V. Zakharov
The paper describes ways for controlling the molecular structure of polyethylene (PE) produced over supported catalysts containing bis(imino)pyridyl complexes of Fe(II) (LFeCl2) and bis(imine) complexes of Ni(II) (*LFeCl2), which are anchored on silica gel modified by the introduction of alumina (SiO2(Al)). Under variation of polymerization conditions over LFeCl2 /SiO2(Al) catalysts, linear PE with different molecular weight and controllable molecular-weight distribution (MWD) was obtained. Homopolymerization of ethylene over *LNiBr2 /SiO2(Al) catalysts led to the formation of branched PE with the molecular-weight and thermophysical characteristics close to the low-density polyethylene produced by ethylene copolymerization with α-olefins over supported metallocene catalysts and supported Zieglertype catalysts. A method was proposed for constructing the supported bicomponent catalysts containing LFeCl2 and *LNiBr2 complexes anchored on the SiO2(Al) support for the deliberate production of polyethylene with the required molecular structure. There are examples of obtaining the linear PE with bimodal MWD on a bicomponent supported catalyst containing two different LFeCl2 complexes, the PE with controllable branching distribution on a bicomponent catalyst synthesized by anchoring LFeCl2 and *LNiBr2 complexes on the SiO2(Al) support, and an example of modifying the industrial chromium oxide catalyst by introducing the LFeCl2 complex for the control of MWD and branching distribution in the produced polyethylene.
{"title":"New Ways for Controlling the Molecular-Weight Characteristics and Branching Distribution in Polyethylene Obtained over Supported Catalysts Containing Bis(imino)pyridyl Complexes of Fe(II) and Bis(imine) Complexes of Ni(II)","authors":"M. A. Matsko, N. V. Semikolenova, V. Zakharov","doi":"10.18412/1816-0387-2022-5-27-39","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-5-27-39","url":null,"abstract":"The paper describes ways for controlling the molecular structure of polyethylene (PE) produced over supported catalysts containing bis(imino)pyridyl complexes of Fe(II) (LFeCl2) and bis(imine) complexes of Ni(II) (*LFeCl2), which are anchored on silica gel modified by the introduction of alumina (SiO2(Al)). Under variation of polymerization conditions over LFeCl2 /SiO2(Al) catalysts, linear PE with different molecular weight and controllable molecular-weight distribution (MWD) was obtained. Homopolymerization of ethylene over *LNiBr2 /SiO2(Al) catalysts led to the formation of branched PE with the molecular-weight and thermophysical characteristics close to the low-density polyethylene produced by ethylene copolymerization with α-olefins over supported metallocene catalysts and supported Zieglertype catalysts. A method was proposed for constructing the supported bicomponent catalysts containing LFeCl2 and *LNiBr2 complexes anchored on the SiO2(Al) support for the deliberate production of polyethylene with the required molecular structure. There are examples of obtaining the linear PE with bimodal MWD on a bicomponent supported catalyst containing two different LFeCl2 complexes, the PE with controllable branching distribution on a bicomponent catalyst synthesized by anchoring LFeCl2 and *LNiBr2 complexes on the SiO2(Al) support, and an example of modifying the industrial chromium oxide catalyst by introducing the LFeCl2 complex for the control of MWD and branching distribution in the produced polyethylene.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83122412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-29DOI: 10.18412/1816-0387-2022-5-53-60
P. Lipin, V. Doronin, O. Potapenko, T. P. Sorokina
A phenol–tetralin model mixture was used to investigate the effect of the oxygen-containing compound on the cracking of aromatic hydrocarbon. The analysis of temperature dependences of the cracking rate constant for tetralin and tetralin in a mixture with phenol indicates that the cracking of tetralin is hindered in the case of its simultaneous conversion with the oxygen-containing compound due to higher adsorptivity of phenol on the catalyst surface. It was found that the presence of phenol in the model mixture changes the composition of liquid products, especially at a low cracking temperature. In addition, the effect of water on conversion of the phenol–tetralin mixture was studied. The presence of water in the model feedstock was shown to decrease the hindering of the aromatic hydrocarbon cracking by the oxygencontaining compound. The results of catalytic transformations revealed that the addition of water increased total conversion of the mixture and conversion of tetralin irrespective of temperature. Essential qualitative differences in the distribution of cracking products of the model mixtures containing or not containing water were not found.
{"title":"Regularities in the Simultaneous Conversion of Phenol and Tetralin During Catalytic Cracking","authors":"P. Lipin, V. Doronin, O. Potapenko, T. P. Sorokina","doi":"10.18412/1816-0387-2022-5-53-60","DOIUrl":"https://doi.org/10.18412/1816-0387-2022-5-53-60","url":null,"abstract":"A phenol–tetralin model mixture was used to investigate the effect of the oxygen-containing compound on the cracking of aromatic hydrocarbon. The analysis of temperature dependences of the cracking rate constant for tetralin and tetralin in a mixture with phenol indicates that the cracking of tetralin is hindered in the case of its simultaneous conversion with the oxygen-containing compound due to higher adsorptivity of phenol on the catalyst surface. It was found that the presence of phenol in the model mixture changes the composition of liquid products, especially at a low cracking temperature. In addition, the effect of water on conversion of the phenol–tetralin mixture was studied. The presence of water in the model feedstock was shown to decrease the hindering of the aromatic hydrocarbon cracking by the oxygencontaining compound. The results of catalytic transformations revealed that the addition of water increased total conversion of the mixture and conversion of tetralin irrespective of temperature. Essential qualitative differences in the distribution of cracking products of the model mixtures containing or not containing water were not found.","PeriodicalId":17783,"journal":{"name":"Kataliz v promyshlennosti","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81280710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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