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Готові списки джерел за темами / Fluorinated metal oxides catalysts / Статті в журналах

Статті в журналах з теми "Fluorinated metal oxides catalysts"

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Автор: Grafiati

Опубліковано: 18 травня 2024

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1

Kemnitz, Erhard, and Dirk-Henning Menz. "Fluorinated metal oxides and metal fluorides as heterogeneous catalysts." Progress in Solid State Chemistry 26, no. 2 (January 1998): 97–153. http://dx.doi.org/10.1016/s0079-6786(98)00003-x.

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2

Chekryshkin, Yu S., T. A. Rozdyalovskaya, Z. R. Ismagilov, M. A. Kerzhentsev, O. A. Tetenova, and A. A. Fedorov. "Deep Oxidation of Fluorinated Hydrocarbons in Molten Catalysts." Eurasian Chemico-Technological Journal 5, no. 2 (April 5, 2016): 137. http://dx.doi.org/10.18321/ectj293.

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Анотація:

<p>The oxidation of fluorine-containing organic substances: fluorocarbon liquid M-1, fluorinated alcohol H(CF<sub>2</sub>)<sub>8</sub>CH<sub>2</sub>OH, and powder polytetrafluoroethylene with air has been studied in melts: NaOH; 43 mol.% LiCl - 33 mol.% NaCl - 24 mol.% KCl (eutectic mixture); (LiCl-NaCl-KCl)eutec. + 10 mass.% V<sub>2</sub>O<sub>5</sub>; (LiCl-NaCl-KCl) eutec. + 15 mass.% V<sub>2</sub>O<sub>5</sub>; 56 mol.% Na<sub>2</sub>CO<sub>3</sub> - 44 mol.% K<sub>2</sub>CO<sub>3</sub> (eutectic), (Na<sub>2</sub>CO<sub>3 </sub>K<sub>2</sub>CO<sub>3</sub>)eutect. + 15 mass.% V<sub>2</sub>O<sub>5</sub>, and K<sub>3</sub>V<sub>5</sub>O<sub>14</sub>. The compositions of the melts have been examined by GC, DTA, chemical analysis and XRD, and they have been shown to change during the reaction, depending on the composition and partial pressure of the gaseous products over the melt surface. The alkali metal chloride melt containing 15 mass.% V<sub>2</sub>O<sub>5</sub> has been found to be most stable to the action of fluorine compounds. Possibility of deep oxidation of fluorine-containing organic substances in melts based on hydroxides, carbonates and chlorides of alkali metals doped with oxides of vanadium has been proved. The process of deep oxidation of fluorinated hydrocarbons is accompanied by formation of an equilibrium mixture containing hydroxides, carbonates, chlorides and fluorides of alkali metals, as well as their vanadates, if V<sub>2</sub>O<sub>5</sub> additive is used. The relative amounts of these substances in molten systems are determined by the partial pressure of oxygen, CO<sub>2 </sub>and water vapor.</p>

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3

Tanuma, T., H. Okamoto, K. Ohnishi, S. Morikawa, and T. Suzuki. "Partially Fluorinated Metal Oxide Catalysts for a Friedel–Crafts-type Reaction of Dichlorofluoromethane with Tetrafluoroethylene." Catalysis Letters 136, no. 1-2 (October 30, 2009): 77–82. http://dx.doi.org/10.1007/s10562-009-0197-3.

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4

Siler, C. G. F., R. J. Madix, and C. M. Friend. "Designing for selectivity: weak interactions and the competition for reactive sites on gold catalysts." Faraday Discussions 188 (2016): 355–68. http://dx.doi.org/10.1039/c5fd00192g.

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A major challenge in heterogeneous catalysis is controlling reaction selectivity, especially in complex environments. When more than one species is present in the gas mixture, the competition for binding sites on the surface of a catalyst is an important factor in determining reaction selectivity and activity. We establish an experimental hierarchy for the binding of a series of reaction intermediates on Au(111) and demonstrate that this hierarchy accounts for reaction selectivity on both the single crystal surface and under operating catalytic conditions at atmospheric pressure using a nanoporous Au catalyst. A partial set of measurements of relative binding has been measured by others on other catalyst materials, including Ag, Pd and metal oxide surfaces; a comparison demonstrates the generality of this concept and identifies differences in the trends. Theoretical calculations for a subset of reactants on Au(111) show that weak van der Waals interactions are key to predicting the hierarchy of binding strengths for alkoxides bound to Au(111). This hierarchy is key to the control of the selectivity for partial oxidation of alcohols to esters on both Au surfaces and under working catalytic conditions using nanoporous gold. The selectivity depends on the competition for active sites among key intermediates. New results probing the effect of fluorine substitution are also presented to extend the relation of reaction selectivity to the hierarchy of binding. Motivated by an interest in synthetic manipulation of fluorinated organics, we specifically investigated the influence of the –CF₃ group on alcohol reactivity and selectivity. 2,2,2-Trifluoroethanol couples on O-covered Au(111) to yield CF₃CH₂O–C(O)(CF₃), but in the presence of methanol or ethanol it preferentially forms the respective 2,2,2-trifluoroethoxy-esters. The ester is not the dominant product in any of these cases, though, indicating that the rate of β-H elimination from adsorbed trifluoroethoxy is slower than that for either adsorbed methoxy or ethoxy, consistent with their relative estimated β-C–H bond strengths. The measured equilibrium constants for the competition for binding to the surface are 2.9 and 0.38 for ethanol and methanol, respectively, vs. 2,2,2-trifluoroethanol, indicating that the binding strength of 2,2,2-trifluoroethoxy is weaker than ethoxy, but stronger than methoxy. These results are consistent with weakening of the interactions between the surface and the alkyl group due to Pauli repulsion of the electron-rich CF₃ group from the surface, which offsets the van der Waals attraction. These experiments provide guiding principles for understanding the effect of fluorination on heterogeneous synthesis and further demonstrate the key role of molecular structure in determining reaction selectivity.

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5

Puzhel, A. O., V. A. Borisov, A. R. Osipov, I. V. Petlin, A. D. Kiselev, and L. N. Adeeva. "Fluoride processing of oil hydrocarbon cracking catalyst with REE concentrate extraction." Izvestiya Vuzov Tsvetnaya Metallurgiya (Universities Proceedings Non-Ferrous Metallurgy) 1, no. 1 (February 11, 2021): 28–35. http://dx.doi.org/10.17073/0021-3438-2021-1-28-35.

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It is proposed to use a spent cracking catalyst of petroleum hydrocarbons containing 1 wt.% of rare earth element (REE) oxides as an alternative REE feed source. The study covers the process of removing silicon in the form of ammonium hexafluorosilicate (NH4)2SiF6 by sintering an oil cracking catalyst sample with NH4F and subsequent (NH4)2SiF6 sublimation to produce an aluminum-containing concentrate of rare earth elements. The orthogonal central compositional planning of the experiment was used to study the effect of three factors: sublimation temperature (350 to 400 °С), duration (40 to 80 min), and weight of the catalyst fluorinated sintered mass (5 to 10 g) on the (NH4)2SiF6 sublimation completeness. Results obtained in the experiment were used to build a second-order model, which correlate with experimental data. The dynamics of (NH4)2SiF6 sublimation removal was determined for sublimation durations of τ = 10, 20, 40 and 80 min at processing temperatures of 350, 375 and 400 °C. The (NH4)2SiF6 removal degree values calculated based on the second-order model for τ = 44, 48, 52, 56, 60, 64, 68, 72, and 76 min fit well the experimental curves. Spectra of fluorinated catalyst samples before and after sublimation were studied using X-ray phase analysis and IR spectroscopy. The data of IR spectroscopy and X-ray phase analysis are in good agreement and show that (NH4)2SiF6, (NH4)3AlF6 and unreacted NH4F are present in the catalyst with NH4F sintered mass, and only aluminum compounds are detected – NH4AlF4 and AlF3 after sublimation. These data indicate the completeness of the sublimation removal of silicon from the catalyst and NH4F sintered mass with NH4AlF4 and AlF3 aluminum compounds only observed after sublimation. REE concentration is 15 % due to silicon removal.

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6

Xi, Jianfei, Jianzhong Liu, Yang Wang, Yourui Hu, Yanwei Zhang, and Junhu Zhou. "Metal Oxides as Catalysts for Boron Oxidation." Journal of Propulsion and Power 30, no. 1 (January 2014): 47–53. http://dx.doi.org/10.2514/1.b35037.

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7

Wang, Fei, Jianzhun Jiang, and Bin Wang. "Recent In Situ/Operando Spectroscopy Studies of Heterogeneous Catalysis with Reducible Metal Oxides as Supports." Catalysts 9, no. 5 (May 23, 2019): 477. http://dx.doi.org/10.3390/catal9050477.

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For heterogeneous catalysis, the metal catalysts supported on reducible metal oxides, especially CeO2 and TiO2, have long been a research focus because of their excellent catalytic performance in a variety of catalytic reactions. Detailed understanding of the promotion effect of reducible metal oxides on catalytic reactions is beneficial to the rational design of new catalysts. The important catalytic roles of reducible metal oxides are attributed to their intimate interactions with the supported metals (e.g., strong metal-support interaction, electronic metal-support interaction) and unique support structures (e.g., oxygen vacancy, reversible valence change, surface hydroxyl). However, the structures of the catalysts and reaction mechanisms are strongly affected by environmental conditions. For this reason, in situ/operando spectroscopy studies under working conditions are necessary to obtain accurate information about the structure-activity relationship. In this review, the recent applications of the in situ/operando spectroscopy methodology on metal catalysts with reducible metal oxides as supports are summarized.

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8

Vasić, Katja, Gordana Hojnik Podrepšek, Željko Knez, and Maja Leitgeb. "Biodiesel Production Using Solid Acid Catalysts Based on Metal Oxides." Catalysts 10, no. 2 (February 17, 2020): 237. http://dx.doi.org/10.3390/catal10020237.

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The development of solid acid catalysts, especially based on metal oxides and different magnetic nanoparticles, gained much awareness recently as a result of the development of different nano-based materials. Solid acid catalysts based on metal oxides are promising for the (trans)esterification reactions of different oils and waste materials for biodiesel production. This review gives a brief overview of recent developments in various solid acid catalysts based on different metal oxides, such as zirconia, zinc, titanium, iron, tungsten, and magnetic materials, where the catalysts are optimized for various reaction parameters, such as the amount of catalyst, molar ratio of oil to alcohol, reaction time, and temperature. Furthermore, yields and conversions for biodiesel production are compared. Such metal-oxide-based solid acid catalysts provide more sustainable, green, and easy-separation synthesis routes with high catalytic activity and reusability than traditionally used catalysts.

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9

Huang, Keke, Yu Sun, Yuan Zhang, Xiyang Wang, Wei Zhang, and Shouhua Feng. "Hollow‐Structured Metal Oxides as Oxygen‐Related Catalysts." Advanced Materials 31, no. 38 (November 14, 2018): 1801430. http://dx.doi.org/10.1002/adma.201801430.

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10

Li, Runze, Lei Luo, Xinlong Ma, Wenlong Wu, Menglin Wang, and Jie Zeng. "Single atoms supported on metal oxides for energy catalysis." Journal of Materials Chemistry A 10, no. 11 (2022): 5717–42. http://dx.doi.org/10.1039/d1ta08016d.

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11

Shin, Seoyoon, Seokhee Lee та Tae Ho Shin. "Metal(Pt, Pd)-Perovskite Oxide(Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ) Hybrid Material As a Bifunctional Electrocatalyst for Lithium-Air Battery". ECS Meeting Abstracts MA2023-02, № 4 (22 грудня 2023): 667. http://dx.doi.org/10.1149/ma2023-024667mtgabs.

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The rapid depletion of fossil fuel resources and growing concerns over climate change have made the development of next-generation batteries a top priority. Among these, Li-O2 batteries have attracted significant interest due to their potential for much higher gravimetric energy storage density compared to other chemical batteries. However, efficient and cost-effective catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are critical for the efficient functioning of these batteries. In recent years, complex perovskite oxides, such as Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF), have been identified as promising candidates for bifunctional catalysts due to their defective structures and excellent oxygen mobility. However, while BSCF exhibits high OER activity, its ORR performance is poor. To address this issue, researchers have turned to metal-oxide composite catalysts, where nanosized metals are deposited on the surface of perovskite oxides, to increase activity and stability towards ORR due to the synergistic effect between metal and oxide support. In this study, we report the development of bifunctional electrocatalysts with highly electrocatalytic activity for ORR and OER. We used a simple wet-chemical processing technique to deposit metal catalysts with superior ORR activity on perovskite oxide-based catalysts with high OER activity. The direct deposition method is an effective way to create a good distribution of metal catalysts, intimate contact between metal catalysts and BSCF perovskite oxide, which may contribute to the creation of a synergistic effect between them. Our results showed that the metal catalysts deposited on perovskite oxides of Pd@BSCF and Pt@BSCF exhibited better ORR activity than others and higher OER activity than the perovskite oxides alone, resulting in much-enhanced bifunctionality through a synergistic effect between the metal catalysts and perovskite oxides. We further investigated the enhanced bifunctional electrocatalytic activity of the metal catalysts deposited perovskite oxides for Li-O2 batteries. The assembled Li-O2 batteries with Pd@BSCF cathode demonstrated lower discharge/charge overpotential (0.8 V at the cutoff capacity of 500 mAh gcat -1) and improved cycling stability (over 70 cycles), indicating the effectiveness of our approach in enhancing the bifunctional activities of ORR and OER for application in electrochemical energy storage and conversion systems. The encouraging results obtained from this study might have been attributed to two mechanisms, namely, the synergistic effect of electronic transfer and RDS/spillover. Our study suggests that the deposition of metal catalysts on the surface of perovskite oxides (Pd@BSCF and Pt@BSCF) is an effective approach to enhance bifunctional activities of ORR and OER, making it a promising strategy for the development of next-generation batteries. Figure 1

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12

Park, Ji-Woo, and Young-Wan Ju. "Evaluation of Bi-Functional Electrochemical Catalytic Activity of Co3O4-CoFe2O4 Composite Spinel Oxide." Energies 16, no. 1 (December 23, 2022): 173. http://dx.doi.org/10.3390/en16010173.

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Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are important for developing energy systems such as fuel cells and metal–air batteries. Precious metal catalysts, such as Pt and IrO2, have been considered electrochemical catalysts because of their excellent activity for the ORR and OER. However, their disadvantages, such as low durability for long-term operation and high price, necessitate the development of alternative electrochemical catalysts. Transition metal oxides with excellent electrical conductivity, high efficiency, and stability have been considered alternative electrochemical catalysts owing to their ORR and OER activities, which are similar to those of precious metal catalysts. Therefore, in this study, composite catalyst materials comprising Co3O4 and CoFe2O4 spinel oxides were synthesized via hydrothermal synthesis. The synthesized composite oxides exhibit bi-functional electrochemical catalytic activity for ORR and OER owing to the large active surface area and increased number of oxygen vacancies via the nanostrain in Co3O4 nanoparticles.

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13

Randhawa, Sukhjinder S., Debyani G. Niyogi, and Rajendar D. Verma. "Reactions of fluorinated acid anhydrides with metal alkoxides and organometallic oxides." Journal of Fluorine Chemistry 54, no. 1-3 (September 1991): 153. http://dx.doi.org/10.1016/s0022-1139(00)83663-5.

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14

Il’in, Alexander A. "SYNTHESIS OF IRON OXIDE FROM METAL POWDERS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 5 (May 21, 2019): 62–70. http://dx.doi.org/10.6060/ivkkt.20196205.6009.

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A comparative analysis of various methods for obtaining highly dispersed iron oxides has been carried out. The advantages and disadvantages of traditional and developing methods of synthesis of iron oxides for catalysts, sorbents and ceramic materials are identified. The advantages of the method of mechanochemical synthesis of obtaining highly dispersed iron oxides for catalysts for the medium-temperature conversion of CO in the production of ammonia and the oxidation of methanol to formaldehyde are shown. The methods of X-ray phase, X-ray structural, synchronous thermal analysis and Mössbauer spectroscopy were used to study the process of mechanochemical oxidation of iron and cast iron powders in order to obtain iron oxides. The phase composition and specific surface area of the obtained oxides are investigated. It was found that in the process of mechanical activation of iron-containing powders in the aquatic environment, the system Fe-Fe3O4-FeOOH is formed. Heat treatment at 450 °C for 6 h causes decomposition of FeOOH to α-Fe2O3 and partial oxidation of metallic iron. By the method of differential dissolution, it was established that the cast iron in the presence of water in a roller-ring vibratory mill for 60 min is oxidized to 77.6%, and the iron is oxidized to 88%. Also in the process of dissolving metal powders in oxalic acid solutions using ultrasound FeC2O4 · 2H2O is formed, which under the conditions of thermolysis decomposes to maghemite – γ-Fe2O3 with the release of CO and CO2, and at 400 °C to hematite – α-Fe2O3. The possibility of using the produced iron oxides for obtaining iron-chromium catalysts for the medium-temperature conversion of CO in the production of ammonia and iron-molybdenum catalysts for formaldehyde synthesis is shown. The CO degree conversion is 92.0% at 340 °C, and the productivity by formaldehyde is 13.0 µmol/(g∙s).

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15

Gao, Yuan, Si-Yan Gong, Baixiao Chen, Wen-Hao Xing, Yan-Fei Fei, Zhong-Ting Hu, and Zhiyan Pan. "Progress in Metal-Organic Framework Catalysts for Selective Catalytic Reduction of NOx: A Mini-Review." Atmosphere 13, no. 5 (May 13, 2022): 793. http://dx.doi.org/10.3390/atmos13050793.

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Nitrogen oxides released from the combustion of fossil fuels are one of the main air pollutants. Selective catalytic reduction technology is the most widely used nitrogen oxide removal technology in the industry. With the development of nanomaterials science, more and more novel nanomaterials are being used as catalysts for the selective reduction of nitrogen oxides. In recent years, metal-organic frameworks (MOFs), with large specific surface areas and abundant acid and metal sites, have been extensively studied in the selective catalytic reduction of nitrogen oxides. This review summarizes recent progress in monometallic MOFs, bimetallic MOFs, and MOF-derived catalysts for the selective catalytic reduction of nitrogen oxides and compares the reaction mechanisms of different catalysts. This article also suggests the advantages and disadvantages of MOF-based catalysts compared with traditional catalysts and points out promising research directions in this field.

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16

Piers, Grumett. "Precious Metal Recovery from Spent Catalysts." Platinum Metals Review 47, no. 4 (October 1, 2003): 163–66. http://dx.doi.org/10.1595/003214003x474163166.

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A new process called AquaCat® for the recovery of precious metals from spent heterogeneous and homogeneous catalysts is described. The process has two stages, the first stage is to determine the precious metal content of a spent heterogeneous catalyst using new direct sampling technology. The second stage involves supercritical water oxidation, during which the carbonaceous material is converted into less noxious compounds, leaving the precious metals as their oxides.

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17

Li, Gen, Guoyong Xu, You Ge, and Shengyu Dai. "Synthesis of fluorinated polyethylene of different topologies via insertion polymerization with semifluorinated acrylates." Polymer Chemistry 11, no. 39 (2020): 6335–42. http://dx.doi.org/10.1039/d0py00993h.

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18

Zhao, Guofeng, Xin-Ping Wu, Ruijuan Chai, Qiaofei Zhang, Xue-Qing Gong, Jun Huang, and Yong Lu. "Tailoring nano-catalysts: turning gold nanoparticles on bulk metal oxides to inverse nano-metal oxides on large gold particles." Chemical Communications 51, no. 27 (2015): 5975–78. http://dx.doi.org/10.1039/c5cc00016e.

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Inverse nano-oxide/large-gold-particle catalysts create an anti-sintering structure with a large interface thereby showing high activity/selectivity for the gas-phase alcohol oxidation with dramatic stability improvement.

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19

Neeft, John P. A., Michiel Makkee, and Jacob A. Moulijn. "Metal oxides as catalysts for the oxidation of soot." Chemical Engineering Journal and the Biochemical Engineering Journal 64, no. 2 (November 1996): 295–302. http://dx.doi.org/10.1016/s0923-0467(96)03138-7.

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20

Dixit, Lalji, D. L. Gerrard, and H. J. Bowley. "Laser Raman Spectra of Transition Metal Oxides and Catalysts." Applied Spectroscopy Reviews 22, no. 2-3 (June 1986): 189–249. http://dx.doi.org/10.1080/05704928608070178.

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21

Witko, Małgorzata, and Renata Tokarz-Sobieraj. "Surface oxygen in catalysts based on transition metal oxides." Catalysis Today 91-92 (July 2004): 171–76. http://dx.doi.org/10.1016/j.cattod.2004.03.029.

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22

Sutormina, E. F., L. A. Isupova, N. A. Kulikovskaya, A. V. Kuznetsova, and N. A. Rudina. "Catalysts based on cordierite modified with transition metal oxides." Kinetics and Catalysis 55, no. 5 (September 2014): 656–64. http://dx.doi.org/10.1134/s0023158414050176.

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23

Hong, Seong-Soo, Gwang-Ho Lee, and Gun-Dae Lee. "Catalytic combustion of benzene over supported metal oxides catalysts." Korean Journal of Chemical Engineering 20, no. 3 (May 2003): 440–44. http://dx.doi.org/10.1007/bf02705544.

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24

Sobczak, Izabela, Katarzyna Jagodzinska, and Maria Ziolek. "Glycerol oxidation on gold catalysts supported on group five metal oxides—A comparative study with other metal oxides and carbon based catalysts." Catalysis Today 158, no. 1-2 (December 2010): 121–29. http://dx.doi.org/10.1016/j.cattod.2010.04.022.

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25

Chae, Jae-Ou, Vladimir Demidiouk, Jae-Won Hwang, Tae Gyun Jung, and V. Ravi. "Catalytic removal of nitric oxides from diesel exhaust over supported metal oxides catalysts." Reaction Kinetics and Catalysis Letters 85, no. 1 (May 2005): 167–73. http://dx.doi.org/10.1007/s11144-005-0257-7.

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26

Mirehbar, Keyvan, Jaime Sanchez Sanchez, Julio J. Lado, and Jesus Palma. "Multi-Metal Oxide Catalyst for Electrochemical Oxidation of Organic Pollutants." ECS Meeting Abstracts MA2023-02, no. 54 (December 22, 2023): 2564. http://dx.doi.org/10.1149/ma2023-02542564mtgabs.

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Анотація:

In recent years, there has been a growing interest in developing highly efficient and stable catalysts for the electro-oxidation of water. These catalysts, besides water electrolysis, could be also a good alternative for removing organic pollutants from water by electro-degradation. Among the innovative groups of catalysts that have been investigated for this purpose, multi-metal oxides have been extensively studied for water electrolysis, but rarely for the direct or indirect oxidation of organic pollutants from water.1 Multi-metal oxide catalysts are composed of two or more metal cations that are chemically bonded to oxygen ions. The combination of different metal cations in a single oxide structure can lead to synergistic effects, which can enhance the catalytic activity and stability of the material. Several types of multi-metal oxide catalysts have been investigated for the electro-oxidation of water, including perovskite oxides, spinel oxides, layered double hydroxides, and mixed metal oxides. Perovskite oxides are a popular class of multi-metal oxide catalysts, which exhibit a wide range of interesting properties, including high catalytic activity, ionic and electronic conductivity, and thermal stability. These properties make perovskite oxides attractive materials for applications in various fields, such as environmental remediation.2 Additionally, the properties of perovskite oxides can be fine-tuned by doping or modifying their chemical composition, morphology, and crystal structure leading to the development of new materials with tailored properties. In this work, multi-metal oxide (perovskite) nanoparticles were synthesized by the hydrothermal method by adjusting the pressure and temperature to obtain multi-metal oxides with controlled crystallinity and morphology. The synthesis was successfully scaled up and electrodes were prepared by impregnating 3D supports with the active materials. The electrocatalytic activity of the prepared electrodes was analyzed by physical and electrochemical characterizations. Moreover, to evaluate the potential application of multi-metal oxide electrodes for organic pollutants removal, phenol was selected as the target pollutant. To complete the research, the effect of different operational conditions (current density, initial pH, initial phenol concentration, and flow rate) on the COD removal of the wastewater in the divided flow cell configuration was investigated. Furthermore, the removal pathway was studied using GC/MS. Acknowledgment: This project has received funding through the HYSOLCHEM project (grant agreement No. 101017928) from the European Union’s Horizon 2020 research and innovation programme. References: (1) Kim, J. S.; Kim, B.; Kim, H.; Kang, K. Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction. Adv. Energy Mater. 2018, 8 (11), 1702774. https://doi.org/10.1002/aenm.201702774. (2) Kumar, A.; Kumar, A.; Krishnan, V. Perovskite Oxide Based Materials for Energy and Environment-Oriented Photocatalysis. ACS Catal. 2020, 10 (17), 10253–10315. https://doi.org/10.1021/acscatal.0c02947.

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27

Wang, Liang, and Feng-Shou Xiao. "Nanoporous catalysts for biomass conversion." Green Chemistry 17, no. 1 (2015): 24–39. http://dx.doi.org/10.1039/c4gc01622j.

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Анотація:

This review is to discuss and evaluate the nanoporous catalysts including functionalized resins, metal oxides, carbons, mesoporous silicas, polydivinylbenzene, and zeolites used in the biomass transformation.

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28

Zhao, Shunzheng, Honghong Yi, Xiaolong Tang, Shanxue Jiang, Fengyu Gao, Bowen Zhang, Yanran Zuo, and Zhixiang Wang. "The Hydrolysis of Carbonyl Sulfide at Low Temperature: A Review." Scientific World Journal 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/739501.

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Catalytic hydrolysis technology of carbonyl sulfide (COS) at low temperature was reviewed, including the development of catalysts, reaction kinetics, and reaction mechanism of COS hydrolysis. It was indicated that the catalysts are mainly involved metal oxide and activated carbon. The active ingredients which can load on COS hydrolysis catalyst include alkali metal, alkaline earth metal, transition metal oxides, rare earth metal oxides, mixed metal oxides, and nanometal oxides. The catalytic hydrolysis of COS is a first-order reaction with respect to carbonyl sulfide, while the reaction order of water changes as the reaction conditions change. The controlling steps are also different because the reaction conditions such as concentration of carbonyl sulfide, reaction temperature, water-air ratio, and reaction atmosphere are different. The hydrolysis of carbonyl sulfide is base-catalyzed reaction, and the force of the base site has an important effect on the hydrolysis of carbonyl sulfide.

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29

Sánchez-Bayo, Alejandra, Rosalía Rodríguez, Victoria Morales, Nima Nasirian, Luis Fernando Bautista, and Gemma Vicente. "Hydrothermal Liquefaction of Microalga Using Metal Oxide Catalyst." Processes 8, no. 1 (December 20, 2019): 15. http://dx.doi.org/10.3390/pr8010015.

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The yield and composition of the biocrude obtained by hydrothermal liquefaction (HTL) of Nannocloropsis gaditana using heterogeneous catalysts were evaluated. The catalysts were based on metal oxides (CaO, CeO2, La2O3, MnO2, and Al2O3). The reactions were performed in a batch autoclave reactor at 320 °C for 10 min with a 1:10 (wt/wt) microalga:water ratio. These catalysts increased the yield of the liquefaction phase (from 94.14 ± 0.30 wt% for La2O3 to 99.49 ± 0.11 wt% for MnO2) as compared with the thermal reaction (92.60 ± 1.20 wt%). Consequently, the biocrude yields also raised in the metal oxides catalysed HTL, showing values remarkably higher for the CaO (49.73 ± 0.9 wt%) in comparison to the HTL without catalyst (42.60 ± 0.70 wt%). The N and O content of the biocrude obtained from non-catalytic HTL were 6.11 ± 0.02 wt% and 10.50 ± 0.50 wt%, respectively. In this sense, the use of the metal oxides decreased the N content of the biocrude (4.62 ± 0.15–5.45 ± 0.11 wt%), although, they kept constant or increased its O content (11.39 ± 2.06–21.68 ± 0.03 wt%). This study shows that CaO, CeO2 and Al2O3 can be promising catalysts based on the remarkable amount of biocrude, the highest values of C, H, heating value, energy recovery, and the lowest content of N, O and S.

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30

Goloboy, James C, and Walter G Klemperer. "Are Particulate Noble-Metal Catalysts Metals, Metal Oxides, or Something In-Between?" Angewandte Chemie International Edition 48, no. 20 (May 4, 2009): 3562–64. http://dx.doi.org/10.1002/anie.200805382.

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31

Melnyk, Yurii, Stepan Melnyk, Halyna Mahorivska, and Viktor Reutskyy. "EFFECT OF PHYSICOCHEMICAL PROPERTIES OF d-METAL OXIDES ON SUNFLOWER OIL TRANSESTERIFICATION." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 2(8) (June 15, 2021): 113–20. http://dx.doi.org/10.20998/2413-4295.2021.02.16.

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The physicochemical indicators of d-metal oxides (NiO, CuO, MnO, FeO, PbO, ZnO) which are heterogeneous catalysts for the transesterification process of sunflower oil triglycerides by ethanol and butan-1-ol have been determined. The available specific surface area, surface acidity and basicity, as well as the hydrogen potential change of the catalyst suspension in water were determined for the oxides. The available specific surface area of the oxides was determined by titration of their aqueous suspension with a solution of methylene blue with a predetermined concentration. The surface acidity and basicity of the catalysts were determined by back titration of samples treated with an aqueous solution of ammonia and acetic acid, respectively. It was found that all investigated d-metal oxides have a low specific surface area. The value of specific surface area is in the range of 0.6-1.5 m2/g. The surface acidity and basicity of the catalysts is 0.13-0.27 mmol/g and 0.019-0.066 mmol/g, respectively. It is shown that the change in the aqueous suspension hydrogen potential of the investigated catalysts relative to the distilled water pH is maximum for NiO and ZnO and it is 0.6-0.65, while for CuO this change is the smallest and it is only 0.3. The character of the pH change curves and the pH values of the oxides suspension in equilibrium condition indicate the presence of weak acid sites in the studied catalysts. The indicated catalysts characteristics are compared with the results obtained in the transesterification process of sunflower oil triglycerides by ethanol and butan-1-ol. It was found that there is a correlation between the surface acidity of catalyst and the reaction initial rate of triglycerides transesterification by ethanol and butan-1-ol. At the same time, such a correlation is absent for the surface basicity of the catalysts. This is consistent with the data on the catalysis of the triglyceride transesterification reaction only by strong major active sites. It is concluded that the transesterification reaction of sunflower oil triglycerides by ethanol and butan-1-ol occurs predominantly on the weak acid centers of the d-metal oxides.

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32

Suda, S., Y. M. Sun, B. H. Liu, Y. Zhou, S. Morimitsu, K. Arai, N. Tsukamoto, M. Uchida, Y. Candra, and Z. P. Li. "Catalytic generation of hydrogen by applying fluorinated-metal hydrides as catalysts." Applied Physics A Materials Science & Processing 72, no. 2 (February 2001): 209–12. http://dx.doi.org/10.1007/s003390100785.

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33

Yu, Yuanting, Yiling Tan, Wen Niu, Shili Zhao, Jiongyue Hao, Yijie Shi, Yingchun Dong, et al. "Advances in Synthesis and Applications of Single-Atom Catalysts for Metal Oxide-Based Gas Sensors." Materials 17, no. 9 (April 24, 2024): 1970. http://dx.doi.org/10.3390/ma17091970.

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As a stable, low-cost, environment-friendly, and gas-sensitive material, semiconductor metal oxides have been widely used for gas sensing. In the past few years, single-atom catalysts (SACs) have gained increasing attention in the field of gas sensing with the advantages of maximized atomic utilization and unique electronic and chemical properties and have successfully been applied to enhance the detection sensitivity and selectivity of metal oxide gas sensors. However, the application of SACs in gas sensors is still in its infancy. Herein, we critically review the recent advances and current status of single-atom catalysts in metal oxide gas sensors, providing some suggestions for the development of this field. The synthesis methods and characterization techniques of SAC-modified metal oxides are summarized. The interactions between SACs and metal oxides are crucial for the stable loading of single-atom catalysts and for improving gas-sensitive performance. Then, the current application progress of various SACs (Au, Pt, Cu, Ni, etc.) in metal oxide gas sensors is introduced. Finally, the challenges and perspectives of SACs in metal oxide gas sensors are presented.

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34

Chrzan, M., D. Chlebda, P. Jodłowski, E. Salomon, A. Kołodziej, A. Gancarczyk, M. Sitarz, and J. Łojewska. "Towards Methane Combustion Mechanism on Metal Oxides Supported Catalysts: Ceria Supported Palladium Catalysts." Topics in Catalysis 62, no. 1-4 (February 2019): 403–12. http://dx.doi.org/10.1007/s11244-019-01143-8.

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35

Jabłońska, Magdalena, and Alejandro Mollá Robles. "A Comparative Mini-Review on Transition Metal Oxides Applied for the Selective Catalytic Ammonia Oxidation (NH3-SCO)." Materials 15, no. 14 (July 7, 2022): 4770. http://dx.doi.org/10.3390/ma15144770.

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The selective catalytic oxidation of NH3 (NH3-SCO) into N2 and H2O is an efficient technology for NH3 abatement in diesel vehicles. However, the catalysts dedicated to NH3-SCO are still under development. One of the groups of such catalysts constituted transition metal-based catalysts, including hydrotalcite-derived mixed metal oxides. This class of materials is characterized by tailored composition, homogenously dispersed mixed metal oxides, exhibiting high specific surface area and thermal stability. Thus, firstly, we give a short introduction to the structure and composition of hydrotalcite-like materials and their applications in NH3-SCO. Secondly, an overview of other transition metal-based catalysts reported in the literature is given, following a comparison of both groups. The challenges in NH3-SCO applications are provided, while the reaction mechanisms are discussed for particular systems.

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36

Walsh, Dominic, Noelia M. Sanchez-Ballester, Katsuhiko Ariga, Akihiro Tanaka, and Mark Weller. "Chelate stabilized metal oxides for visible light photocatalyzed water oxidations." Green Chemistry 17, no. 2 (2015): 982–90. http://dx.doi.org/10.1039/c4gc01604a.

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Lactate-stabilized calcium manganese oxide and cobalt hydroxide nanoparticles were utilized as catalysts in visible light photocatalyzed water oxidations. Chelated bi-metallic catalysts captured decomposed cobalt based electron acceptor and gave prolonged two stage reactions. Hydroxylated Co–lactates gave high TOF and O₂ yields. Chelation produced extended reactions, higher yields and reduced waste.

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37

Jonson, Bo, Bernd Rebenstorf, Ragnar Larsson, and Michel Primet. "Infrared Emission Spectroscopy Studies of Metal Oxide Catalysts." Applied Spectroscopy 40, no. 6 (August 1986): 798–803. http://dx.doi.org/10.1366/0003702864508287.

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The spectral changes of a series of metal oxides, resulting from their oxidation of toluene, were studied by infrared emission spectroscopy. Comparative investigations were carried out with a grating spectrophotometer and with an interferometric Fourier transform spectrophotometer. The latter was found to be superior in the present kind of experiments.

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38

Zhu, Ying Ying, Zeng Xu, Guo Dong Yao, Yun Jun, and Fang Ming Jin. "Conversion of Microalgae under Hydrothermal Conditions." Advanced Materials Research 860-863 (December 2013): 501–5. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.501.

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A new and green technology for converting microalgae to high value-added chemicals with solid metal oxides catalysts under hydrothermal conditions was proposed. The results indicated that ZrO2, among other test catalysts, can prominently boost the production of acetic acid and a highest yield of 24% was achieved at 300 °C for 2 h with a filling rate of 50%. The metal oxides catalyst provided a promising solution to obtain acetic acid from microalgae conversion.

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39

Bratan, Veronica, Anca Vasile, Paul Chesler, and Cristian Hornoiu. "Insights into the Redox and Structural Properties of CoOx and MnOx: Fundamental Factors Affecting the Catalytic Performance in the Oxidation Process of VOCs." Catalysts 12, no. 10 (September 28, 2022): 1134. http://dx.doi.org/10.3390/catal12101134.

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Анотація:

Volatile organic compound (VOC) abatement has become imperative nowadays due to their harmful effect on human health and on the environment. Catalytic oxidation has appeared as an innovative and promising approach, as the pollutants can be totally oxidized at moderate operating temperatures under 500 °C. The most active single oxides in the total oxidation of hydrocarbons have been shown to be manganese and cobalt oxides. The main factors affecting the catalytic performances of several metal-oxide catalysts, including CoOx and MnOx, in relation to the total oxidation of hydrocarbons have been reviewed. The influence of these factors is directly related to the Mars–van Krevelen mechanism, which is known to be applied in the case of the oxidation of VOCs in general and hydrocarbons in particular, using transitional metal oxides as catalysts. The catalytic behaviors of the studied oxides could be closely related to their redox properties, their nonstoichiometric, defective structure, and their lattice oxygen mobility. The control of the structural and textural properties of the studied metal oxides, such as specific surface area and specific morphology, plays an important role in catalytic applications. A fundamental challenge in the development of efficient and low-cost catalysts is to choose the criteria for selecting them. Therefore, this research could be useful for tailoring advanced and high-performance catalysts for the total oxidation of VOCs.

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40

Choi, Goune, and Bonjae Koo. "Research Trends in Development of Highly Active Single Metal Oxide Catalyst for Oxidative Coupling of Methane." Ceramist 24, no. 4 (December 31, 2021): 438–45. http://dx.doi.org/10.31613/ceramist.2021.24.4.05.

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The conversion of methane to a value-added chemical is important for methane utilization and industrial demand for primary chemicals. Oxidative coupling of methane (OCM) to C2 hydrocarbons is one of the most attractive ways to use natural gas. However, it is difficult to obtain higher C2 yield in classic OCM reaction due to a favorable COx formation. Regarding this, various catalysts for OCM have been studied to fulfill desirable C2 yields. In this review, we briefly overview the single metal oxide types of OCM catalysts (alkaline-earth metal oxides and rare-earth metal oxides) and highlight the characteristics of catalysts in OCM reaction such as methane activation, surface basicity and lattice oxygen.

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41

Han, Binghong, and Yang Shao-Horn. "(Invited) In-Situ Study of the Activated Lattice Oxygen Redox Reactions in Metal Oxides during Oxygen Evolution Catalysis." ECS Meeting Abstracts MA2018-01, no. 32 (April 13, 2018): 1935. http://dx.doi.org/10.1149/ma2018-01/32/1935.

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Promoting the oxygen evolution reaction (OER) near room temperature is critical to improve the efficiency of many electrochemical energy storage and conversion techniques, such as water splitting and rechargeable metal-air batteries. Nowadays, researchers have developed many non-precious metal oxides as highly active OER catalysts, including many perovskite oxides (ABO3) of first-row transition metals such as LaCoO3-δ (LCO), SrCoO3-δ (SCO), and Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF). However, understanding the interaction between oxides catalysts and water, which determines the stability and activity of the oxide OER catalysts, is still challenging. Here we report the systematic investigation between water and various perovskite oxides with different electronic structures, using a series of in situ characterization techniques including on-line electrochemical mass spectrometry (OLEMS), environmental transmission electron microscopy (ETEM), and pH-dependent electrochemical tests. It is find that having an oxygen 2p-band closer to the Fermi level and increasing the covalency of metal-oxygen bonds could facilitate the redox reaction of lattice oxygen in perovskites during OER catalysis. In the oxides such as SCO and BSCF with activated lattice oxygen in the OER process, we observe the evolving of 18O-labeled lattice oxygen in OLEMS, the strong pH dependency of OER kinetics in electrochemical measurements, and the structural oscillation in ETEM, which all indicate a new oxygen-site OER mechanism that makes the perovskites more active and less stable. While in the oxides such as LCO with no lattice oxygen activation, all of the above phenomena are missing, implying a stable surface with traditional metal-site OER mechanism. Observing the perovskites in situ during OER allows us to better understand the interaction between electrolytes and oxides, providing us a deeper insight into the stability and active site of oxide catalysts for OER.

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42

Joharian, Monika, Ali Morsali, Alireza Azhdari Tehrani, Lucia Carlucci, and Davide M. Proserpio. "Water-stable fluorinated metal–organic frameworks (F-MOFs) with hydrophobic properties as efficient and highly active heterogeneous catalysts in aqueous solution." Green Chemistry 20, no. 23 (2018): 5336–45. http://dx.doi.org/10.1039/c8gc02367k.

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43

Sun, Qiang, Zhong Wang, Da Wang, Zhe Hong, Mingdong Zhou, and Xuebing Li. "A review on the catalytic decomposition of NO to N2 and O2: catalysts and processes." Catalysis Science & Technology 8, no. 18 (2018): 4563–75. http://dx.doi.org/10.1039/c8cy01114a.

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Recent advances in the catalytic decomposition of NO have been overviewed and divided into three categories: metal oxide catalysts (including perovskites and rare earth oxides), supported metal oxide catalysts (including alkali metals, cobalt oxide and noble metals) and Cu-ZSM-5.

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44

Arandiyan, H. R., and M. Parvari. "Studies on mixed metal oxides solid solutions as heterogeneous catalysts." Brazilian Journal of Chemical Engineering 26, no. 1 (March 2009): 63–74. http://dx.doi.org/10.1590/s0104-66322009000100007.

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45

Wang, Jing, Yiru Mao, LiZhi Zhang, Yonglong Li, Wenming Liu, Qingxiang Ma, Daishe Wu, and Honggen Peng. "Remarkable basic-metal oxides promoted confinement catalysts for CO2 reforming." Fuel 315 (May 2022): 123167. http://dx.doi.org/10.1016/j.fuel.2022.123167.

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46

YAMASHITA, Takehiko, Kohshiroh MIZUNO, Tomonaga UENO, Tomoyuki ISHIKAWA, and Kunihiko TAKEDA. "Flame Retardancy of Polylactic Acid Blended with Metal Oxides Catalysts." KOBUNSHI RONBUNSHU 65, no. 4 (2008): 288–94. http://dx.doi.org/10.1295/koron.65.288.

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47

Masud, Sarif, Maryam Zarei, Martha Laura Lopez, Jorge Gardea-Torresdey, C. V. Ramana, and Geoffrey B. Saupe. "Photoreduction of metallic co-catalysts onto novel semiconducting metal oxides." Materials Science and Engineering: B 174, no. 1-3 (October 2010): 66–70. http://dx.doi.org/10.1016/j.mseb.2010.07.002.

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48

Chen, Hao, Yifan Sun, Shize Yang, Hui Wang, Wojciech Dmowski, Takeshi Egami, and Sheng Dai. "Self-regenerative noble metal catalysts supported on high-entropy oxides." Chemical Communications 56, no. 95 (2020): 15056–59. http://dx.doi.org/10.1039/d0cc05860b.

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Анотація:

A reversible temperature-dependent dissolution–exsolution process was discovered for noble metal species supported on high-entropy oxides, which indicates the potential to exploit the enhanced entropic effects to access self-regenerative catalysts.

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49

Wang, Bing, Huan Zhang, Feifei Wang, Xingaoyuan Xiong, Kun Tian, Yubo Sun, and Tingting Yu. "Application of Heterogeneous Catalytic Ozonation for Refractory Organics in Wastewater." Catalysts 9, no. 3 (March 5, 2019): 241. http://dx.doi.org/10.3390/catal9030241.

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Catalytic ozonation is believed to belong to advanced oxidation processes (AOPs). Over the past decades, heterogeneous catalytic ozonation has received remarkable attention as an effective process for the degradation of refractory organics in wastewater, which can overcome some disadvantages of ozonation alone. Metal oxides, metals, and metal oxides supported on oxides, minerals modified with metals, and carbon materials are widely used as catalysts in heterogeneous catalytic ozonation processes due to their excellent catalytic ability. An understanding of the application can provide theoretical support for selecting suitable catalysts aimed at different kinds of wastewater to obtain higher pollutant removal efficiency. Therefore, the main objective of this review article is to provide a summary of the accomplishments concerning catalytic ozonation to point to the major directions for choosing the catalysts in catalytic ozonation in the future.

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50

Chernykh, Maria, Maria Grabchenko, Alexey Knyazev, and Grigory Mamontov. "Cordierite-Supported Transition-Metal-Oxide-Based Catalysts for Ozone Decomposition." Crystals 13, no. 12 (December 11, 2023): 1674. http://dx.doi.org/10.3390/cryst13121674.

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Cordierite-based supported noble-metal-free catalysts for ozone decomposition are elaborated. The cordierite ceramic surface is pretreated with oxalic acid and NaOH, and Mn-Cu-Ni oxide catalysts are prepared by the impregnation method. The mass ratio of the supported oxides in the resulting catalysts is MnO2:CuO:NiO = 3:2:1, and their loadings are from 1.8 to 7.0 wt.%. The pretreated supports and catalysts are characterized by low-temperature N2 adsorption, scanning electron microscopy (SEM), powder X-ray diffraction analysis (XRD), and temperature-programmed reduction with H2 (TPR-H2). The catalysts are tested in ozone decomposition with high airflow rates (20 and 50 L/min) and with initial ozone concentrations of 1 and 2 ppm at temperatures in the range of 25–120 °C. It is shown that a combined treatment of cordierite with oxalic acid and NaOH leads to a developed porous structure and stabilization of supported Mn-Cu-Ni oxides in a highly dispersed state. The high activity of catalysts in ozone decomposition at room temperature and high airflow is demonstrated. The developed catalysts can be recommended for application in purification of air from the ozone because of their high catalytic activity, high mechanical stability, and relatively low weight and cost.

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