Pub Date : 2024-09-11DOI: 10.1134/s0036024424701310
A. L. Kustov, Ch. A. Garifullina, A. A. Zalyatdinov, A. A. Shesterkina, M. A. Tedeeva, S. F. Dunaev, L. M. Kustov
Abstract
Aromatic hydrocarbons (benzene, toluene, xylene) are valuable intermediates in the chemical and petrochemical industries, so the conversion of butane into aromatics is an important catalytic process from both scientific and industrial viewpoints. In addition to the production of aromatic compounds, the production of hydrogen during aromatization of lower alkanes is also of interest. This review describes industrial processes and presents the main achievements in the field of scientific research into butane aromatization on heterogeneous catalysts over the past 15 years. Current problems and possible directions of studies on the development of catalysts for aromatization of C4 hydrocarbons are also discussed.
{"title":"Recent Advances in the Field of Butane Aromatization in the Presence of Heterogeneous Catalysts","authors":"A. L. Kustov, Ch. A. Garifullina, A. A. Zalyatdinov, A. A. Shesterkina, M. A. Tedeeva, S. F. Dunaev, L. M. Kustov","doi":"10.1134/s0036024424701310","DOIUrl":"https://doi.org/10.1134/s0036024424701310","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Aromatic hydrocarbons (benzene, toluene, xylene) are valuable intermediates in the chemical and petrochemical industries, so the conversion of butane into aromatics is an important catalytic process from both scientific and industrial viewpoints. In addition to the production of aromatic compounds, the production of hydrogen during aromatization of lower alkanes is also of interest. This review describes industrial processes and presents the main achievements in the field of scientific research into butane aromatization on heterogeneous catalysts over the past 15 years. Current problems and possible directions of studies on the development of catalysts for aromatization of C<sub>4</sub> hydrocarbons are also discussed.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701528
A. V. Syugaev, M. A. Eryomina
Abstract
Electrochemical impedance spectroscopy is used to study the effect of potential (E) on capacitance (C) of porous tantalum coated with a layer of amorphous Ta2O5. It is shown that there is a positive linear dependence 1/C2 in a wide range of potentials, and its slope can be used to control an oxide layer in porous tantalum. It is established that the transformation of the oxide layer during annealing in the temperature range 100–700°C strongly affects 1/C2(E)-graphics. Annealing at temperatures of 100–500°C raises the concentration of oxygen vacancies in the oxide layer due to partial transfer of oxygen into tantalum, resulting in lower slope of the 1/C2(E) plots as compared with initial non-annealed sample. After annealing at temperatures of 600 and 700°C, a TaO phase forms in the oxide film, accompanied by a strong increase in capacitance and a weak dependence on potential due to the emergence of a high concentration of donors in the oxide film. The promise is shown of using 1/C2(E) dependences to control a layer of oxide in porous tantalum, which could be useful in tantalum capacitor technology.
{"title":"EIS Study of Oxide Layer in Porous Tantalum","authors":"A. V. Syugaev, M. A. Eryomina","doi":"10.1134/s0036024424701528","DOIUrl":"https://doi.org/10.1134/s0036024424701528","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Electrochemical impedance spectroscopy is used to study the effect of potential (<i>E</i>) on capacitance (<i>C</i>) of porous tantalum coated with a layer of amorphous Ta<sub>2</sub>O<sub>5</sub>. It is shown that there is a positive linear dependence 1/<i>C</i><sup>2</sup> in a wide range of potentials, and its slope can be used to control an oxide layer in porous tantalum. It is established that the transformation of the oxide layer during annealing in the temperature range 100–700°C strongly affects 1/<i>C</i><sup>2</sup>(<i>E</i>)-graphics. Annealing at temperatures of 100–500°C raises the concentration of oxygen vacancies in the oxide layer due to partial transfer of oxygen into tantalum, resulting in lower slope of the 1/<i>C</i><sup>2</sup>(<i>E</i>) plots as compared with initial non-annealed sample. After annealing at temperatures of 600 and 700°C, a TaO phase forms in the oxide film, accompanied by a strong increase in capacitance and a weak dependence on potential due to the emergence of a high concentration of donors in the oxide film. The promise is shown of using 1/<i>C</i><sup>2</sup>(<i>E</i>) dependences to control a layer of oxide in porous tantalum, which could be useful in tantalum capacitor technology.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701334
Yu. K. Tovbin
Abstract
Expressions for the thermodynamic potentials (TPs) of small systems are traditionally used in thermodynamics by analogy with TPs of ordinary macro-phases. This form of introducing TPs for small systems eliminates their specificity consisting in the presence of dimensional dependences for TP values and all other thermodynamic functions. To take into account the sizes of small systems in the traditional method of introducing TPs, it is necessary to explicitly reflect the presence of an interface and the associated heterogeneity of the internal local properties of a small system. The general case is discussed when dimensional dependences of TPs of small systems in limited volumes are introduced, with macroscopic concepts of the phase and the interface non-autonomy being preserved. Options are considered to introduce size dependences into TPs of small droplets and separated fluid phases inside pores.
{"title":"Thermodynamic Potentials of Small Separated Systems","authors":"Yu. K. Tovbin","doi":"10.1134/s0036024424701334","DOIUrl":"https://doi.org/10.1134/s0036024424701334","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Expressions for the thermodynamic potentials (TPs) of small systems are traditionally used in thermodynamics by analogy with TPs of ordinary macro-phases. This form of introducing TPs for small systems eliminates their specificity consisting in the presence of dimensional dependences for TP values and all other thermodynamic functions. To take into account the sizes of small systems in the traditional method of introducing TPs, it is necessary to explicitly reflect the presence of an interface and the associated heterogeneity of the internal local properties of a small system. The general case is discussed when dimensional dependences of TPs of small systems in limited volumes are introduced, with macroscopic concepts of the phase and the interface non-autonomy being preserved. Options are considered to introduce size dependences into TPs of small droplets and separated fluid phases inside pores.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701462
Harsimranjot Kaur
Abstract
Pure and Co (10 mol %)-doped α-Fe2O3 (Hematite) nanostructures have been effectively synthesized by hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) have been used for the analysis of crystallography, morphology and functional groups of synthesized samples. The banding nature of synthesized samples is analyzed by Fourier transform infrared spectroscopy (FTIR). Powder XRD results reveal the formation of rhombohedral structured α-Fe2O3 nanostructures. Effect of dopant and synthesis conditions, such as precursor change and time duration of heating temperature has been investigated on the morphology of pure and Co (10 mol %)-doped α-Fe2O3 nanostructures. It has been observed that the addition of dopant, change of precursor and time duration of the heating temperature of hydrothermal treatment can effectively control the morphology of NPs. Methylene dye (MB) has been used as a test contaminant in aqueous solution to determine the photo-catalytic potential of Fe2O3 nanostructures under visible light.
{"title":"Effect of Synthesis Conditions and Doping on Properties of Hematite Nanostructures","authors":"Harsimranjot Kaur","doi":"10.1134/s0036024424701462","DOIUrl":"https://doi.org/10.1134/s0036024424701462","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Pure and Co (10 mol %)-doped α-Fe<sub>2</sub>O<sub>3</sub> (Hematite) nanostructures have been effectively synthesized by hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) have been used for the analysis of crystallography, morphology and functional groups of synthesized samples. The banding nature of synthesized samples is analyzed by Fourier transform infrared spectroscopy (FTIR). Powder XRD results reveal the formation of rhombohedral structured α-Fe<sub>2</sub>O<sub>3</sub> nanostructures. Effect of dopant and synthesis conditions, such as precursor change and time duration of heating temperature has been investigated on the morphology of pure and Co (10 mol %)-doped α-Fe<sub>2</sub>O<sub>3</sub> nanostructures. It has been observed that the addition of dopant, change of precursor and time duration of the heating temperature of hydrothermal treatment can effectively control the morphology of NPs. Methylene dye (MB) has been used as a test contaminant in aqueous solution to determine the photo-catalytic potential of Fe<sub>2</sub>O<sub>3</sub> nanostructures under visible light.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701516
S. A. Ryzhkin, A. V. Kapitonov, S. V. Kurbatova, M. N. Zemtsova
Abstract
The authors study the laws governing the sorption of some derivatives of 1,2,3,4-tetrahydroquinoline and pyridazino[4,5-c]quinoline from water–acetonitrile solutions on an octadecyl-functionalized silica gel under reverse-phase high-performance liquid chromatography. The physicochemical characteristics and retention factors of sorbates at different acetonitrile concentrations in the eluent are determined. Dependences of the change in the retention factor as a function of sorbate structure and eluent composition are analyzed.
{"title":"Sorption of 1,2,3,4-Tetrahydroquinoline and Pyridazino[4,5-c]quinoline Derivatives under Conditions of Reversed-Phase High-Performance Liquid Chromatography","authors":"S. A. Ryzhkin, A. V. Kapitonov, S. V. Kurbatova, M. N. Zemtsova","doi":"10.1134/s0036024424701516","DOIUrl":"https://doi.org/10.1134/s0036024424701516","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The authors study the laws governing the sorption of some derivatives of 1,2,3,4-tetrahydroquinoline and pyridazino[4,5-c]quinoline from water–acetonitrile solutions on an octadecyl-functionalized silica gel under reverse-phase high-performance liquid chromatography. The physicochemical characteristics and retention factors of sorbates at different acetonitrile concentrations in the eluent are determined. Dependences of the change in the retention factor as a function of sorbate structure and eluent composition are analyzed.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701449
O. G. Zamyshlyaeva, R. V. Rumyantsev, G. K. Fukin, L. S. Medvedeva, S. S. Sologubov, A. V. Markin
Abstract
Hydrogermylation is used to obtain new compound, tris(pentafluorophenyl)-2-pyridylethylgermane. The structure is confirmed via IR and NMR spectroscopy, and X-ray diffraction analysis. Thermophysical properties are determined using DSC and TGA. Two polymorphic modifications (triclinic and monoclinic) of tris(pentafluorophenyl)-2-pyridylethylgermane are discovered. It is shown that the triclinic modification is more energetically advantageous than monoclinic modification. The topology of the electron density of tris(pentafluorophenyl)-2-pyridylethylgermane is studied theoretically and experimentally. an intramolecular Ge(1)-N(1) contact is discovered and its energy is estimated from the topology of electron density.
{"title":"Tris(Pentafluorophenyl)-2-Pyridilethylgermane: Synthesis, Identification, and Quantum Chemical Calculations","authors":"O. G. Zamyshlyaeva, R. V. Rumyantsev, G. K. Fukin, L. S. Medvedeva, S. S. Sologubov, A. V. Markin","doi":"10.1134/s0036024424701449","DOIUrl":"https://doi.org/10.1134/s0036024424701449","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Hydrogermylation is used to obtain new compound, tris(pentafluorophenyl)-2-pyridylethylgermane. The structure is confirmed via IR and NMR spectroscopy, and X-ray diffraction analysis. Thermophysical properties are determined using DSC and TGA. Two polymorphic modifications (triclinic and monoclinic) of tris(pentafluorophenyl)-2-pyridylethylgermane are discovered. It is shown that the triclinic modification is more energetically advantageous than monoclinic modification. The topology of the electron density of tris(pentafluorophenyl)-2-pyridylethylgermane is studied theoretically and experimentally. an intramolecular Ge(1)-N(1) contact is discovered and its energy is estimated from the topology of electron density.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701346
L. N. Skvortsova, I. A. Tikhonova, K. A. Dychko, T. S. Minakova, K. A. Bolgaru
Abstract
The autowave combustion of ferroalloys (ferrovanadium, aluminum ferrochrome, ferroaluminum silicocirconium) in nitrogen are used to determine the phase composition of iron-containing metal–ceramic composites based on nitrides of aluminum, chromium, and vanadium. The content of iron on the surfaces of the composites is measured via scanning electron microscopy using an X-ray micro analyzer. The Hammett and Tanabe indicator reveals that aprotic Lewis basic centers (pKa −0.29) and strong acidic Brønsted centers (pKa 2.01, 4.1) dominate on the surfaces of chromium nitride-based composites. The surfaces of the samples based on vanadium nitride have many acidic Brønsted centers (pKa 1.3–5.5). The correlation between the adsorption activity of composites and the studied organic pollutants (metamizole, cinnarizine, methylene blue, and methyl orange), plus the type and number of acid-base active centers on the surfaces of the materials, testifies to the dominance of chemisorption, for which mechanisms are proposed. The strong oxidative destruction of organic pollutants (64–96%) upon UV irradiation is due to the adsorption properties of the composites and the combination of heterogeneous photocatalysis and the homogeneous Fenton process.
摘要 利用铁合金（钒铁、铝铬铁、硅锆铝铁）在氮气中的自波燃烧来确定以铝、铬和钒的氮化物为基础的含铁金属陶瓷复合材料的相组成。使用 X 射线显微分析仪通过扫描电子显微镜测量复合材料表面的铁含量。哈米特和塔纳贝指标显示，氮化铬基复合材料表面主要存在钝态路易斯碱性中心（pKa -0.29）和强酸性布氏中心（pKa 2.01，4.1）。氮化钒基样品的表面有许多酸性布氏中心（pKa 1.3-5.5）。复合材料的吸附活性与所研究的有机污染物（甲咪唑、辛那利嗪、亚甲基蓝和甲基橙）之间的相关性，以及材料表面酸碱活性中心的类型和数量，证明了化学吸附的主导地位，并提出了相关机制。在紫外线照射下，有机污染物被强氧化破坏（64-96%），这是由于复合材料的吸附特性以及异相光催化和均相芬顿过程的结合。
{"title":"Acid–Base Properties and Adsorption Activity of Iron-Containing Composites in the Photocatalytic Degradation of Organic Pollutants","authors":"L. N. Skvortsova, I. A. Tikhonova, K. A. Dychko, T. S. Minakova, K. A. Bolgaru","doi":"10.1134/s0036024424701346","DOIUrl":"https://doi.org/10.1134/s0036024424701346","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The autowave combustion of ferroalloys (ferrovanadium, aluminum ferrochrome, ferroaluminum silicocirconium) in nitrogen are used to determine the phase composition of iron-containing metal–ceramic composites based on nitrides of aluminum, chromium, and vanadium. The content of iron on the surfaces of the composites is measured via scanning electron microscopy using an X-ray micro analyzer. The Hammett and Tanabe indicator reveals that aprotic Lewis basic centers (p<i>K</i><sub>a</sub> −0.29) and strong acidic Brønsted centers (p<i>K</i><sub>a</sub> 2.01, 4.1) dominate on the surfaces of chromium nitride-based composites. The surfaces of the samples based on vanadium nitride have many acidic Brønsted centers (p<i>K</i><sub>a</sub> 1.3–5.5). The correlation between the adsorption activity of composites and the studied organic pollutants (metamizole, cinnarizine, methylene blue, and methyl orange), plus the type and number of acid-base active centers on the surfaces of the materials, testifies to the dominance of chemisorption, for which mechanisms are proposed. The strong oxidative destruction of organic pollutants (64–96%) upon UV irradiation is due to the adsorption properties of the composites and the combination of heterogeneous photocatalysis and the homogeneous Fenton process.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Near infrared (NIR) Y2Ti2O7:Ce3+/Cr3+/Nd3+ phosphors were synthesized using a solid-state reaction technique. NIR luminescent performance of Y2Ti2O7:Cr3+/Nd3+ phosphors was improved by doping with Ce3+ ions. The emission intensity of Y2T2O7:Cr3+/Nd3+/Ce3+ phosphors is significantly higher than that of Y2Ti2O7:Cr3+/Nd3+ phosphors. The external quantum efficiency and internal quantum efficiency of Y2Ti2O7:0.5% Cr3+/0.7% Nd3+/1.5% Ce3+ are 16 and 22.8%, respectively. The luminescent mechanisms of the Y2Ti2O7:Cr3+/Nd3+ and Y2T2O7:Cr3+/Nd3+/Ce3+ phosphors were investigated. As a result, the effective energy transfer process from Cr3+ to Nd3+ ions exists in Y2Ti2O7:Cr3+/Nd3+ phosphors, while the effective energy transfer process from Ce3+ to Cr3+ and Nd3+ ions exists in Y2T2O7:Cr3+/Nd3+/Ce3+ phosphors. NIR emission intensities of LED devices assembled with Y2Ti2O7:0.5% Cr3+/0.7% Nd3+/1.5% Ce3+ phosphors are better than those of LED devices assembled with Y2Ti2O7:0.5% Cr3+/0.7% Nd3+ phosphors at different work currents. In addition, the temperature-sensitive behavior of Y2Ti2O7:Cr3+/Nd3+ phosphors was also studied. Their LIR and Sa values monotonically increase in the temperature range of 303–393 K. The maximum Sa values of Y2Ti2O7:0.5% Cr3+/0.5% Nd3+, Y2Ti2O7:0.5% Cr3+/0.7% Nd3+, Y2Ti2O7:0.5% Cr3+/1.0% Nd3+, Y2Ti2O7:0.5% Cr3+/2.0% Nd3+ samples are 0.79 × 10–2, 0.88 × 10–2, 1.24 × 10–4, and 2.53 × 10–3 K–1, respectively.
{"title":"Near-Infrared Emission Properties and LED Applications of Y2Ti2O7:Cr3+/Nd3+ Phosphors Improved by Doping with Ce3+ Ions","authors":"Shanshan Cong, Hongquan Yu, Xiao Gao, Zhanwen Han, Baojiu Chen, Jiashi Sun, Xiangping Li","doi":"10.1134/s0036024424701565","DOIUrl":"https://doi.org/10.1134/s0036024424701565","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Near infrared (NIR) Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:Ce<sup>3+</sup>/Cr<sup>3+</sup>/Nd<sup>3+</sup> phosphors were synthesized using a solid-state reaction technique. NIR luminescent performance of Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup> phosphors was improved by doping with Ce<sup>3+</sup> ions. The emission intensity of Y<sub>2</sub>T<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup>/Ce<sup>3+</sup> phosphors is significantly higher than that of Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup> phosphors. The external quantum efficiency and internal quantum efficiency of Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/0.7% Nd<sup>3+</sup>/1.5% Ce<sup>3+</sup> are 16 and 22.8%, respectively. The luminescent mechanisms of the Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup> and Y<sub>2</sub>T<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup>/Ce<sup>3+</sup> phosphors were investigated. As a result, the effective energy transfer process from Cr<sup>3+</sup> to Nd<sup>3+</sup> ions exists in Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup> phosphors, while the effective energy transfer process from Ce<sup>3+</sup> to Cr<sup>3+</sup> and Nd<sup>3+</sup> ions exists in Y<sub>2</sub>T<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup>/Ce<sup>3+</sup> phosphors. NIR emission intensities of LED devices assembled with Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/0.7% Nd<sup>3+</sup>/1.5% Ce<sup>3+</sup> phosphors are better than those of LED devices assembled with Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/0.7% Nd<sup>3+</sup> phosphors at different work currents. In addition, the temperature-sensitive behavior of Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:Cr<sup>3+</sup>/Nd<sup>3+</sup> phosphors was also studied. Their LIR and <i>S</i><sub>a</sub> values monotonically increase in the temperature range of 303–393 K. The maximum <i>S</i><sub>a</sub> values of Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/0.5% Nd<sup>3+</sup>, Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/0.7% Nd<sup>3+</sup>, Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/1.0% Nd<sup>3+</sup>, Y<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>:0.5% Cr<sup>3+</sup>/2.0% Nd<sup>3+</sup> samples are 0.79 × 10<sup>–2</sup>, 0.88 × 10<sup>–2</sup>, 1.24 × 10<sup>–4</sup>, and 2.53 × 10<sup>–3</sup> K<sup>–1</sup>, respectively.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Producing high-density fuel of alkylated decalins from hydrodeoxygenation (HDO) of naphthalene derivatives is an environmentally friendly but still challenging method. Herein, a bifunctional Ru/HZSM-5 catalyst was fabricated by acid treatment (citric acid, oxalic acid, nitric acid) to effectively synthesize the alkylated decalins via HDO of naphthalene derivative. Acid treatment adjusted the acidic site distribution of Ru/HZSM-5. Nitric acid treatment (NA) resulted in more abundance of weak acidic sites which was beneficial for the dehydration process in HDO, and the lowest ratio of BAS/LAS to promote the hydrogenation of alkylated octalins, the rate-determining step of HDO. NA-treated Ru/HZSM-5 showed the highest HDO activity with the highest selectivity of 1,2-dimethyldecalin (74%). Besides, it also presents good HDO activity of naphthalene derivatives to produce high-density hydrocarbons. Therefore, Ru/HZ5-NA is a promising catalyst for the production of alkylated decalins and other high-value biofuels and chemicals.
{"title":"Optimized Acidic Sites Distribution for Selective Synthesis of Alkylated Decalins over Acid-Treated Ru/HZSM-5","authors":"Guiling Wu, Wenli Zhao, Xinyue Yang, Xiaopo Niu, Zhen Guo, Danni Liu, Qingfa Wang","doi":"10.1134/s003602442470136x","DOIUrl":"https://doi.org/10.1134/s003602442470136x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Producing high-density fuel of alkylated decalins from hydrodeoxygenation (HDO) of naphthalene derivatives is an environmentally friendly but still challenging method. Herein, a bifunctional Ru/HZSM-5 catalyst was fabricated by acid treatment (citric acid, oxalic acid, nitric acid) to effectively synthesize the alkylated decalins via HDO of naphthalene derivative. Acid treatment adjusted the acidic site distribution of Ru/HZSM-5. Nitric acid treatment (NA) resulted in more abundance of weak acidic sites which was beneficial for the dehydration process in HDO, and the lowest ratio of BAS/LAS to promote the hydrogenation of alkylated octalins, the rate-determining step of HDO. NA-treated Ru/HZSM-5 showed the highest HDO activity with the highest selectivity of 1,2-dimethyldecalin (74%). Besides, it also presents good HDO activity of naphthalene derivatives to produce high-density hydrocarbons. Therefore, Ru/HZ5-NA is a promising catalyst for the production of alkylated decalins and other high-value biofuels and chemicals.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0036024424701498
A. E. Karnaeva, I. V. Minenkova, O. I. Grinevich, Yu. V. Minenkov, A. A. Otletov, A. N. Stavrianidi, A. K. Buryak
Abstract
Thermodynamic characteristics are calculated for new products of the transformation of N,N‑dimethylhydrazine, the values of which can be used to reliably identify these compounds and predict their periods of retention. For the first time, the ideal gas–rigid rotator–harmonic oscillator approximation is used to predict entropies in the gas phase, and the Feller–Peterson–Dixon approach is used to obtain reliable enthalpies of formation in the gas phase for the considered compounds. Retention of the considered isomeric triazole derivatives under conditions of reverse phase high-performance liquid chromatography correlates well with the obtained values of thermodynamic characteristics.
{"title":"Predicting the Thermodynamic Characteristics of New Products of N,N-Dimethylhydrazine Transformation in the Gas Phase","authors":"A. E. Karnaeva, I. V. Minenkova, O. I. Grinevich, Yu. V. Minenkov, A. A. Otletov, A. N. Stavrianidi, A. K. Buryak","doi":"10.1134/s0036024424701498","DOIUrl":"https://doi.org/10.1134/s0036024424701498","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Thermodynamic characteristics are calculated for new products of the transformation of <i>N</i>,<i>N</i>‑dimethylhydrazine, the values of which can be used to reliably identify these compounds and predict their periods of retention. For the first time, the ideal gas–rigid rotator–harmonic oscillator approximation is used to predict entropies in the gas phase, and the Feller–Peterson–Dixon approach is used to obtain reliable enthalpies of formation in the gas phase for the considered compounds. Retention of the considered isomeric triazole derivatives under conditions of reverse phase high-performance liquid chromatography correlates well with the obtained values of thermodynamic characteristics.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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