Artigos de revistas: "Molybdenum oxide catalysts"

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Del Río, José Daniel, Gustavo Andrés Durán, Álvaro Orjuela Londoño, Francisco José Sánchez Castellanos e Carlos Alberto Guerrero Fajardo. "Partial oxidation of methane to formaldehyde on MoO3, Fe2O3 and ferromolybdenum catalysts". Ingeniería e Investigación 27, n.º 1 (1 de janeiro de 2007): 19–24. http://dx.doi.org/10.15446/ing.investig.v27n1.14773.

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One of the main challenges for catalysis has been direct methane conversion to useful products such as methanol and formaldehyde. Formaldehyde is currently produced by a three-step industrial process with syngas and methanol as intermediate products. MoO3 Fe2O3, and Fe2(MoO4)3 catalysts were used with four different Mo/Fe molar ratios (0.5, 1, 1.5, 2) in this work. The ferromolybdenum catalyst was prepared by coprecipitation. Pure oxides are more active; however they are not formaldehyde selective, but carbon oxide (CO, CO2) selective. The ferromolybdenum catalysts showed better HCHO selectivity at low conversions; the molybdenum oxide content did not show increased in catalytic activity. Increased reaction temperature did not increase formaldehyde selectivity.

2

Garg, Pulkit. "A Review of the Catalysts Used in Propane Ammoxidation Reaction to Produce Acrylonitrile". International Journal for Research in Applied Science and Engineering Technology 11, n.º 3 (31 de março de 2023): 2083–103. http://dx.doi.org/10.22214/ijraset.2023.49891.

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Abstract: Background: Various catalysts were studied to synthesize acrylonitrile via propane ammoxidation. The catalysts used for this process can be categorized as antimony-based catalysts, molybdenum-based catalysts, zeolites, nitride material catalysts, and other catalysts. The catalyst which was proved to be an efficient catalyst among all other catalysts is the mixed metal oxide catalyst MoVNbTe due to its high selectivity and yield.

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Klienkov, Alexey V., e Alexander A. Petukhov. "Obtaining molybdenyl glycolate using ethanol as a salting out solvent". Butlerov Communications 59, n.º 9 (30 de setembro de 2019): 66–70. http://dx.doi.org/10.37952/roi-jbc-01/19-59-9-66.

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The global production of propylene oxide is more than 8 million tons/year and is increasing by more than 5% annually. Almost all domestic propylene oxide (72 thousand tons/year) is produced at PJSC Nizhnekamskneftekhim (Russia) according to one of the variants of the Halcon process – epoxidation of propylene with ethylbenzene hydroperoxide (HPEB) in the presence of a molybdenum catalyst. One of the most important tasks arising in improving the process for the joint production of styrene and propylene oxide at PJSC Nizhnekamskneftekhim (Russia) is the search and development of new catalysts and catalytic systems, one of the stages of this process – the epoxidation of propylene with HPEB. The complex molybdenum catalyst used in the production of propylene oxide, having high activity and selectivity, has several disadvantages, namely: low dissolved molybdenum content, high consumption of ethylbenzene hydroperoxide for its production, and instability during storage. Thus, the problem of obtaining a catalyst with a higher content of dissolved molybdenum and increasing the stability of the catalytic complex, i.e. development of new catalytic systems with the best technological and technical and economic indicators. An analysis of the scientific and technical literature and patent publications showed that in the synthesis of a complex molybdenum catalyst, various molybdenum compounds of both organic and inorganic nature can be used. During the study, molybdenum-containing solutions based on ammonium paramolybdate and monoethylene glycol were tested, distillation distillation products prepared by distilling off excess monoethylene glycol by strengthening under vacuum. Molybdenyl glycolate was isolated by salting out with ethanol from a distillation bottoms product.

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Aghayeva, N. I., e S. A. Mammadkhanova. "DEPENDENCE OF ACTIVITY OF BINARY Mo-V-O CATALYSTS IN THE REACTION OF DEHYDROGENATION AND OXIDATION OF ISOPROPYL ALCOHOL ON ACIDIC SURFACE PROPERTIES". Chemical Problems 21, n.º 4 (2023): 388–95. http://dx.doi.org/10.32737/2221-8688-2023-4-388-395.

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The reaction of dehydrogenation and oxidative dehydrogenation of isopropyl alcohol on molybdenum-vanadium oxide catalysts has been studied. It found that the dependences of isopropyl alcohol conversion and propylene yields on the atomic ratio of molybdenum to vanadium in reaction of dehydrogenation of isopropyl alcohol have the form of a curve with two maxima on samples Mo-V=2-8 and Mo-V=6-4. To characterize the acidic properties of the surface of molybdenum-vanadium oxide catalysts, their activity in the reaction of butene-1 isomerization into butenes-2 was also studied. It showed that on molybdenum-vanadium catalysts the dependence of the yield of 2-butenes on the ratio of molybdenum to vanadium also had the form of a curve with two maxima. The activities of molybdenumvanadium oxide catalysts were compared with their acidic properties. It revealed that on binary molybdenum-vanadium oxide catalysts in the reaction of isopropyl alcohol dehydrogenation the increase of surface acidity led to the increase in acetone yield and the decrease in propylene yield. In the reaction of oxidative dehydrogenation of isopropyl alcohol, the increase in surface acidity led to the increase in acetone yield, while propylene yield practically did not change.

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Thrane, Joachim, Lars Fahl Lundegaard, Pablo Beato, Uffe Vie Mentzel, Max Thorhauge, Anker Degn Jensen e Martin Høj. "Alkali Earth Metal Molybdates as Catalysts for the Selective Oxidation of Methanol to Formaldehyde—Selectivity, Activity, and Stability". Catalysts 10, n.º 1 (6 de janeiro de 2020): 82. http://dx.doi.org/10.3390/catal10010082.

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Alkali earth metal molybdates (MMoO4, M = Mg, Ca, Sr, and Ba) were investigated as catalysts for the selective oxidation of methanol to formaldehyde in the search for more stable alternatives to the current industrial iron molybdate catalyst. The catalysts were prepared by either sol-gel synthesis or co-precipitation with both stoichiometric ratio (Mo:M = 1.0) and 10 mol% to 20 mol% excess Mo (Mo:M = 1.1 to 1.2). The catalysts were characterized by X-ray diffraction (XRD), nitrogen physisorption, Raman spectroscopy, temperature programmed desorption of CO2 (CO2-TPD), and inductively coupled plasma (ICP). The catalytic performance of the catalysts was measured in a lab-scale, packed bed reactor setup by continuous operation for up to 100 h on stream at 400 °C. Initial selectivities towards formaldehyde of above 97% were achieved for all samples with excess molybdenum oxide at MeOH conversions between 5% and 75%. Dimethyl ether (DME) and dimethoxymethane (DMM) were the main byproducts, but CO (0.1%–2.1%) and CO2 (0.1%–0.4%) were also detected. It was found that excess molybdenum oxide evaporated from all the catalysts under operating conditions within 10 to 100 h on stream. No molybdenum evaporation past the point of stoichiometry was detected.

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Farooq, Muhammad, Anita Ramli e Duvvuri Subbarao. "Evaluation of the Physiochemical Properties of Molybdenum Supported Catalysts". Advanced Materials Research 488-489 (março de 2012): 206–10. http://dx.doi.org/10.4028/www.scientific.net/amr.488-489.206.

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Molybdenum catalysts supported on γ-Al2O3and γ-Al2O3-MgO mixed oxide with varying loading of MgO (5, 10, 15, 20 wt% with respect to γ-Al2O3) were prepared successfully by wet impregnation method. The physiochemical properties of these synthesized Mo catalysts were studied by various analytical techniques such as N2adsorption–desorption (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Temperature-programmed reduction (TPR).The results showed that the addition of MgO into the support affected the binding energies of the elements and reducibility of the metal oxides formed after calcination of catalyst samples due to change in metal-support interaction. Further, the characterization techniques showed that the active metal was well dispersed on the surface of support material.

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Zazhigalov, V. A., K. Wieczorek-Ciurowa, O. V. Sachuk e I. V. Bacherikova. "Mechanochemystry as advanced methodology in green chemistry for applied catalysis". Catalysis and Petrochemistry, n.º 31 (2021): 1–16. http://dx.doi.org/10.15407/kataliz2021.31.001.

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In this survey we have assessed how mechanochemistry techniques comply with the aims of Green Chemistry to minimise the use of environmentally damaging reactants and unwanted by-products. In the publications the preparation of vanadium-phosphorus oxides as industrial catalysts for maleic anhydride production from n-butane and perspective catalysts of phthalic anhydride manufacture by direct n-pentane oxidation were analyzed. It is shown that mechanochemical activation and synthesis reduces the amount of harmful waste used in the production of the catalyst and increases its effectiveness. Improvement of a catalyst’s properties, help limit production of harmful emissions such as carbon oxides and hydrocarbons. It was established that mechanochemical treatment can by successfully used in the process of industrial vanadium-phosphorus oxide catalysts modification or in the process of introduction in its composition of additives which lead to increase of activity and selectivity of hydrocarbons oxidation. The possibility of the mechanochemistry use in the vanadium-titanium oxide catalysts preparation which are the base catalysts in industrial phthalic anhydride production from o-xylene was determined. It was established that mechanochemical treatment of the vanadium and titanium oxides mixture permits to delete the nitrogen oxides emission in atmosphere and prepared catalysts demonstrate the same phthalic anhydride yield but at low reraction temperature. Catalysts, manufactured by mechanochemical treatment (on the base of molybdenum oxide), provide new techniques for producing compounds as exemplified by the direct oxidation of benzene to form phenol which can replace industrial two-step process from cumene or proposed process of benzene oxidation by N2O. Mechanochemistry treatment could produce catalysts which eliminated the need to use highly toxic nitrogen oxides as reducing agents. The article describes activating Cu-Ce-O catalysts which reduce the temperature of the process for removing carbon monoxide from exhaust gases and as a method for purifying hydrogen u sed in fuel cells. Finally, there is a description of mechanochemically treated catalysts, containing metals and supported on stainless steel supports which are used to remove aromatic hydrocarbons from water sewers.

8

Halawy, Samih A., Mohamed A. Mohamed e Geoffrey C. Bond. "Characterization of unsupported molybdenum oxide-cobalt oxide catalysts". Journal of Chemical Technology & Biotechnology 58, n.º 3 (24 de abril de 2007): 237–45. http://dx.doi.org/10.1002/jctb.280580306.

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Navajas, Alberto, Inés Reyero, Elena Jiménez-Barrera, Francisca Romero-Sarria, Jordi Llorca e Luis M. Gandía. "Catalytic Performance of Bulk and Al2O3-Supported Molybdenum Oxide for the Production of Biodiesel from Oil with High Free Fatty Acids Content". Catalysts 10, n.º 2 (1 de fevereiro de 2020): 158. http://dx.doi.org/10.3390/catal10020158.

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Non-edible vegetable oils are characterized by high contents of free fatty acids (FFAs) that prevent from using the conventional basic catalysts for the production of biodiesel. In this work, solid acid catalysts are used for the simultaneous esterification and transesterification with methanol of the FFAs and triglycerides contained in sunflower oil acidified with oleic acid. Molybdenum oxide (MoO3), which has been seldom considered as a catalyst for the production of biodiesel, was used in bulk and alumina-supported forms. Results showed that bulk MoO3 is very active for both transesterification and esterification reactions, but it suffered from severe molybdenum leaching in the reaction medium. When supported on Al2O3, the MoO3 performance improved in terms of active phase utilization and stability though molybdenum leaching remained significant. The improvement of catalytic performance was ascribed to the establishment of MoO3-Al2O3 interactions that favored the anchorage of molybdenum to the support and the formation of new strong acidic centers, although this effect was offset by a decrease of specific surface area. It is concluded that the development of stable catalysts based on MoO3 offers an attractive route for the valorization of oils with high FFAs content.

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Shilov, Ivan, Andrey Smirnov, Olga Bulavchenko e Vadim Yakovlev. "Effect of Ni–Mo Carbide Catalyst Formation on Furfural Hydrogenation". Catalysts 8, n.º 11 (19 de novembro de 2018): 560. http://dx.doi.org/10.3390/catal8110560.

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High-loading Ni–Mo carbide catalysts were prepared by the modified gel-combustion method under various thermal treatment conditions. All samples were studied by X-ray diffraction (XRD) analysis, which showed that the catalysts could contain cubic and hexagonal molybdenum carbides, nickel, nickel oxide and Ni–Mo solid solutions, depending on the thermal treatment conditions. Study of catalyst activity and selectivity in the hydrogenation of furfural was carried out in a batch reactor at 150 °C and hydrogen pressure 6.0 MPa. Analysis of the reaction products showed that the highest yields of 2-methylfuran (2-MF) and furfuryl alcohol (FA) were achieved using catalysts synthesized by calcination of the nickel-molybdenum-carbon precursor at 400 °С with the following reduction in a stream of hydrogen at 600 °C. The best results for production of FA with a yield of 80 mol % and 2-MF with a yield of 29 mol % were observed using Ni6MoC–SiO2 (400/600) and Ni1MoC–SiO2 (400/600) catalysts, respectively. It has been shown that the addition of nickel to the carbide molybdenum catalyst significantly increases the activity of the catalytic systems. In addition, nickel also contributes to the formation of products formed by hydrogenation of the aromatic ring tetrahydrofurfuryl alcohol (THFA) and 2-methyltetrahydrofuran (2-MTHF).

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Gul, O. O., P. D. Polikarpova, A. V. Akopyan e A. V. Anisimov. "Bimetallic Heterogeneous Catalysts for the Oxidation of Sulfur-Containing Compounds with Hydrogen Peroxide". Кинетика и катализ 64, n.º 5 (1 de setembro de 2023): 609–17. http://dx.doi.org/10.31857/s0453881123050039.

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Bimetallic heterogeneous catalysts based on SBA-15 containing molybdenum and iron oxides were studied in the oxidation reactions of model mixtures of organosulfur compounds. Iron additive (in the form of iron(III) oxide) in the amount of 0.05 wt % to the catalyst 5%Mo/SBA-15 turns out to be the most effective. The catalysts were confirmed by a complex of physicochemical methods: low-temperature adsorption-desorption of nitrogen, X-ray phase analysis, transmission electron microscopy, X-ray photoelectron spectroscopy. The influence of the main oxidation parameters (reaction time, temperature, composition and amount of catalyst, amount of oxidizer) on the conversion of dibenzothiophene as a component of the model mixture weas investigated. Optimal oxidation conditions that allow to achieve total transformation of the substrate were selected: H2O2 : S = 2 : 1, 0.5 wt % of the catalyst FeMo/SBA-15, 60 min, 60°C; catalysts can be used for at least 5 cycles without loss of activity during their intermediate washing from oxidation products.

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Zhou, Linyuan, Huiru Yang, Xiangze Du e Changwei Hu. "Regulating the Hydrodeoxygenation Activity of Molybdenum Carbide with Different Diamines as Carbon Sources". Catalysts 14, n.º 2 (10 de fevereiro de 2024): 138. http://dx.doi.org/10.3390/catal14020138.

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The hydrodeoxygenation (HDO) of renewable fats or fatty acids into alkanes is a powerful measure to address energy and environmental crises. Molybdenum carbide-based catalysts are promising due to their platinum-like noble metal electronic properties. In this paper, Mo2C catalysts were prepared by one-step carbonization of amine molybdenum oxide (AMO) precursors using diamines with different carbon chain lengths as ligands. The physical and chemical properties and the HDO catalytic activity of the catalysts were investigated. The results indicate that as the carbon chain of diamines in the precursor increases, the carbon content of the catalysts in the surface and bulk phase increases. The Mo2C-12 catalyst exhibited excellent catalytic performance, with a palmitic acid conversion rate of 100% and an alkane selectivity of 96.6%, which are attributed to the smallest particle size, largest pore size, and synergistic effect of carbon. This work provides a simple and safe method for regulating the surface properties of Mo2C catalysts.

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Xamidov, Anvar, Farhodjon Hoshimov, Shavkat Mamatkulov, Khakimjan Butanov, Mirakhmat Yunusov e Olim Ruzimuradov. "Catalytic Activity of Ni, Co, Mo Supported Anodic Aluminum Oxide Nanocomposites". Bulletin of Chemical Reaction Engineering & Catalysis 15, n.º 3 (10 de novembro de 2020): 845–52. http://dx.doi.org/10.9767/bcrec.15.3.8480.845-852.

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Nanostructured catalysts based on porous aluminum oxide (PAO) and some 3d metals, such as: nickel, cobalt, and molybdenum, have been obtained by anodic oxidation and impregnation. The synthesis of porous aluminum oxide with a highly ordered pore structure with pore sizes of 50 nm and a thickness of 50 µm is carried out by the method of two-stage anodic oxidation. The catalysts are obtained by impregnation of 3d metals into nanosized pores of aluminum oxide. The obtained catalysts based on nickel and porous Al2O3 are studied by scanning electron microscopy (SEM-EDX). The results of SEM-EDX analysis shows that a spongy structure with filament sizes of 100 nanometers containing particles of 3d metals formed on the surface of the aluminum oxide matrix. The results are presented on the activity of nickel and heterogenic cobalt and molybdenum nanoparticles in the reaction of hydrogenation of hexene to hexane. The results show that the yield temperature of the hexane is decreased and the yield of hexane is observed at 200 °C with Ni/Al2O3 catalysts, and a similar yield of hexane mass is achieved at temperatures higher than 250 °C with Co-Mo/Al2O3 and traditional nickel catalysts on kieselguhr. Copyright © 2020 BCREC Group. All rights reserved

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Sapienza, R., W. Slegeir e D. Mahajan. "When does molybdenum oxide equal molybdenum hexacarbonyl?: Relations between heterogeneous and homogeneous molybdenum catalysts in syngas catalysis". Polyhedron 5, n.º 1-2 (janeiro de 1986): 249–55. http://dx.doi.org/10.1016/s0277-5387(00)84918-9.

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Zazhigalov, V. A., K. Wieczorek-Ciurowa, O. V. Sachuk, E. A. Diyuk e I. V. Bacherikova. "Mechanochemical Synthesis of Nanodispersed Molybdenum Oxide Catalysts". Theoretical and Experimental Chemistry 54, n.º 4 (setembro de 2018): 225–34. http://dx.doi.org/10.1007/s11237-018-9567-5.

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Milbum, Diane R., Bruce D. Adkins e Burtron H. Davis. "Alumina supported molybdenum and tungsten oxide catalysts." Applied Catalysis A: General 119, n.º 2 (novembro de 1994): 205–22. http://dx.doi.org/10.1016/0926-860x(94)85192-1.

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Makayeva, Nursaya, Gaukhar Yergaziyeva, Moldir Anisova, Zhanna Shaimerden e Kusman Dossumov. "Effect of the interaction of components in a nickel-molybdenum catalyst on its activity in decomposition of methane to hydrogen". Chemical Bulletin of Kazakh National University, n.º 3 (20 de setembro de 2022): 12–19. http://dx.doi.org/10.15328/cb1281.

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This work is devoted to the study of the activity of monometallic (Fe/Al2O3) and bimetallic (Fe-Mo/Al2O3) catalysts supported to carrier γ- Al2O3. It has been discovered that the bimetallic catalyst is more active than the monometallic catalyst in the methane decomposition reaction. The results of the influence of molybdenum oxide on the activity of Fe/Al2O3 catalyst in the methane decomposition reaction in the temperature range 500-850°C have been obtained. It has been determined that the addition of molybdenum oxide in the amount of 5 wt. % of the iron catalyst composition leads to an increase in the catalytic activity of the sample in the reaction of methanedecomposition to hydrogen at relatively low temperatures. Compared to Fe/Al2O3 on the FeMo/Al2O3 catalyst at a reaction temperature of 750°C, methane conversionincreases from 8% to 98%, hydrogen yield from 5% to 57%. The increased field of activity Fe-Mo/Al2O3catalyst in the decomposition of methane to hydrogen compared to Fe/Al2O3 catalysts is due to an increase in the dispersity of the active phases of the catalyst, as well as the formation of an easily reduced Fe2(MоО4)3 phase, according to XRD, TPR-H2, and BET methods.

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Kon, Yoshihiro, Tadahiro Fujitani, Takuya Nakashima, Toru Murayama e Wataru Ueda. "Versatile etherification of alcohols with allyl alcohol by a titanium oxide-supported molybdenum oxide catalyst: gradual generation from titanium oxide and molybdenum oxide". Catalysis Science & Technology 8, n.º 18 (2018): 4618–25. http://dx.doi.org/10.1039/c8cy00613j.

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Mukhtarova, Mariyam, Maria Golubeva, Alexey Sadovnikov e Anton Maximov. "Guaiacol to Aromatics: Efficient Transformation over In Situ-Generated Molybdenum and Tungsten Oxides". Catalysts 13, n.º 2 (23 de janeiro de 2023): 263. http://dx.doi.org/10.3390/catal13020263.

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The development of catalysts for the hydrodeoxygenation of bio-based feedstocks is an important step towards the production of fuels and chemicals from biomass. This paper describes in situ-generated bulk molybdenum and tungsten oxides in the hydrodeoxygenation of the lignin-derived compound guaiacol. The catalysts obtained were studied using powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transition electron microscopy, diffuse reflectance infrared Fourier transform spectroscopy, and Raman spectroscopy. The use of metal carbonyls as precursors was shown to promote the formation of amorphous molybdenum oxide and crystalline tungsten phosphide under hydrodeoxygenation conditions. The catalysts’ activity was investigated under various reaction conditions (temperature, H2 pressure, solvent). MoOx was more active in the partial and full hydrodeoxygenation of guaiacol at temperatures of 200–380 °C (5 MPa H2, 6 h). However, cyclohexane, which is an undesirable product, was formed in significant amounts using MoOx (5 MPa H2, 6 h), while WOx was more selective to aromatics. When using dodecane as a solvent (380 °C, 5 MPa H2, 6 h), the benzene-toluene-xylenes fraction was obtained with a 96% yield over the WOx catalyst.

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Markovits, Iulius I. E., Michael H. Anthofer, Helene Kolding, Mirza Cokoja, Alexander Pöthig, Andreas Raba, Wolfgang A. Herrmann, Rasmus Fehrmann e Fritz E. Kühn. "Efficient epoxidation of propene using molecular catalysts". Catal. Sci. Technol. 4, n.º 11 (2014): 3845–49. http://dx.doi.org/10.1039/c4cy01066c.

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Sriatun, A. Darmawan, H. Susanto e Widayat. "THE NiO AND MoO3 ENRICHED ZSM-5 AS CATALYST FOR THE HYDROCRACKING OF COCONUT OIL INTO BIO-JET FRACTION". Rasayan Journal of Chemistry 15, n.º 01 (2022): 437–47. http://dx.doi.org/10.31788/rjc.2022.1516704.

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ZSM-5 was enriched with NiO (nickel oxide) or MoO3 (molybdenum oxide) and used as a catalyst to increase selectivity towards the bio-jet fuel fraction from the hydrocracking of coconut oil. NiO and MoO3 were incorporated into ZSM-5 through wet impregnation at various concentrations of 0.5–5% (wt.). The catalyst material characteristics were analyzed using XRD (X-ray Diffraction), TEM (Transmission Electron Microscope), and nitrogen gas adsorption instruments. The catalyst activity was observed through a hydrocracking reaction at a temperature of 475 °C for 3 hours, using coconut oil as feed and the catalyst concentration was 2 (wt.%). The results showed that NiO and MoO3 were distributed successfully into ZSM-5. Catalyst's catalytic activity was strongly influenced by the amount of NiO and MoO3 embedded into ZSM-5. The Ni-1, Ni-5, Mo-1, Mo-3, Mo-4, and Mo-5 catalysts increased the selectivity towards the bio-jet fraction by 55%, 34%, 49%, 37%, 36%, and 62%, respectively when compared to ZSM-5.

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Aid, Tiina, Mihkel Koel, Margus Lopp e Merike Vaher. "Metal-Catalyzed Degradation of Cellulose in Ionic Liquid Media". Inorganics 6, n.º 3 (10 de agosto de 2018): 78. http://dx.doi.org/10.3390/inorganics6030078.

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Biomass conversion to 5-hydroxymethylfurfural (HMF) has been widely investigated as a sustainable alternative to petroleum-based feedstock, since it can be efficiently converted to fuel, plastic, polyester, and other industrial chemicals. In this report, the degradation of commercial cellulose, the isomerization of glucose to fructose, and the conversion of glucose to HMF in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl]) using metal catalysts (CrCl3, ZnCl2, MgCl2) as well as tungsten and molybdenum oxide-based polyoxometalates (POM) were investigated. Tungsten and molybdenum oxide-based POMs in ionic liquids (IL) were able to degrade cellulose to majority glucose and epimerize glucose to mannose (in the case of the molybdenum oxide-based POM). A certain amount of glucose was also converted to HMF. The tungsten oxide-based POM in IL showed good activity for cellulose degradation but the overall products yield remained 28.6% lower than those obtained using CrCl3 as a catalyst. Lowering the cellulose loading did not significantly influence the results and the addition of water to the reaction medium decreased the product yields remarkably.

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Burch*, R., e R. Swarnakar. "Oxidative dehydrogenation of ethane on vanadium-molybdenum oxide and vanadium-niobium-molybdenum oxide catalysts". Applied Catalysis 70, n.º 1 (janeiro de 1991): 129–48. http://dx.doi.org/10.1016/s0166-9834(00)84159-7.

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Zhao, Zhao Hui, Han Bo Zou e Wei Ming Lin. "Influence of Final Nitriding Temperature on the Preparation and the Catalytic Performance of CoMoN_x/CNTs for Ammonia Decomposition". Advanced Materials Research 557-559 (julho de 2012): 1514–17. http://dx.doi.org/10.4028/www.scientific.net/amr.557-559.1514.

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A series of cobalt-molybdenum nitride catalysts were prepared using Co-Mo oxide precursors via temperature-programmed reaction in N2-H2 mixed gases. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, temperature-programmed desorption of H2. Their catalytic performance was evaluated in the model reaction of ammonia decomposition. The influence of the final nitriding temperatures on the surface properties and the catalytic perfomance of CoMoNx/CNTs were described. The catalyst nitrided at 650°C shows the best catalytic performance. The results indicated that a suitable final nitriding temperature contributes directly to the formation of nitrides and favor the catalyst activity.

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Khazzal Hummadi, Khalid, Karim H. Hassan e Phillip C. H. Mitchell. "Selectivity and Activity of Iron Molybdate Catalysts in Oxidation of Methanol". Journal of Engineering Research [TJER] 6, n.º 1 (1 de junho de 2009): 1. http://dx.doi.org/10.24200/tjer.vol6iss1pp1-7.

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The selectivity and activity of iron molybdate catalysts prepared by different methods are compared with those of a commercial catalyst in the oxidation of methanol to formaldehyde in a continuous tubular bed reactor at 200-350 oC (473-623 oK), 10 atm (1013 kPa), with a methanol-oxygen mixture fixed at 5.5% by volume methanol: air ratio. The iron(III) molybdate catalyst prepared by co-precipitation and filtration had a selectivity towards formaldehyde in methanol oxidation comparable with a commercial catalyst; maximum selectivity (82.3%) was obtained at 573oK when the conversion was 59.7%. Catalysts prepared by reacting iron (III) and molybdate by kneading or precipitation followed by evaporation, omitting a filtration stage, were less active and less selective. The selectivity-activity relationships of these catalysts as a function of temperature were discussed in relation to the method of preparation, surface areas and composition. By combing this catalytic data with data from the patent literature we demonstrate a synergy between iron and molybdenum in regard to methanol oxidation to formaldehyde; the optimum composition corresponded to an iron mole fraction 0.2-0.3. The selectivity to formaldehyde was practically constant up to an iron mole fraction 0.3 and then decreased at higher iron concentrations. The iron component can be regarded as the activity promoter. The iron molybdate catalysts can thus be related to other two-component MoO3-based selective oxidation catalysts, e.g. bismuth and cobalt molybdates. The iron oxide functions as a relatively basic oxide abstracting, in the rate-controlling step, a proton from the methyl of a bound methoxy group of chemisorbed methanol. It was proposed that a crucial feature of the sought after iron(III) molybdate catalyst is the presence of -O-Mo-O-Fe-O-Mo-O- groups as found in the compound Fe2(MoO4)3 and for Fe3+ well dispersed in MoO3 generally. At the higher iron(III) concentrations the loss of selectivity is due to the presence of iron oxide patches or particles which catalyze the total oxidation of methanol, and the loss of activity to blocking of molybdenum sites.

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Klissurski, D., V. Rives, Y. Pesheva, I. Mitov e N. Abadzhjieva. "Iron-chromium-molybdenum oxide catalysts for methanol oxidation". Catalysis Letters 18, n.º 3 (1993): 265–71. http://dx.doi.org/10.1007/bf00769446.

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Riad, M., e S. Mikhail. "Dehydrogenation of cyclohexane over molybdenum/mixed oxide catalysts". Catalysis Communications 9, n.º 6 (março de 2008): 1398–403. http://dx.doi.org/10.1016/j.catcom.2007.12.001.

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Fierro, J. L. G., E. Salazar e J. A. Legarreta. "Characterization of silica-supported uranium-molybdenum oxide catalysts". Surface and Interface Analysis 7, n.º 2 (abril de 1985): 97–104. http://dx.doi.org/10.1002/sia.740070208.

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Bartlett, B., C. Soto, R. Wu e W. T. Tysoe. "The activity of molybdenum and molybdenum oxide model catalysts for olefin metathesis". Catalysis Letters 21, n.º 1-2 (1993): 1–10. http://dx.doi.org/10.1007/bf00767364.

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Nunes, Martinique S., Diana M. Gomes, Ana C. Gomes, Patrícia Neves, Ricardo F. Mendes, Filipe A. Almeida Paz, André D. Lopes, Martyn Pillinger, Anabela A. Valente e Isabel S. Gonçalves. "A Molybdenum(VI) Complex of 5-(2-pyridyl-1-oxide)tetrazole: Synthesis, Structure, and Transformation into a MoO3-Based Hybrid Catalyst for the Epoxidation of Bio-Olefins". Catalysts 13, n.º 3 (10 de março de 2023): 565. http://dx.doi.org/10.3390/catal13030565.

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The discovery of heterogeneous catalysts synthesized in easy, sustainable ways for the valorization of olefins derived from renewable biomass is attractive from environmental, sustainability, and economic viewpoints. Here, an organic–inorganic hybrid catalyst formulated as [MoO3(Hpto)]·H2O (2), where Hpto = 5-(2-pyridyl-1-oxide)tetrazole, was prepared by a hydrolysis–condensation reaction of the complex [MoO2Cl2(Hpto)]∙THF (1). The characterization of 1 and 2 by FT-IR and Raman spectroscopies, as well as 13C solid-state NMR, suggests that the bidentate N,O-coordination of Hpto in 1 (forming a six-membered chelate ring, confirmed by X-ray crystallography) is maintained in 2, with the ligand coordinated to a molybdenum oxide substructure. Catalytic studies suggested that 2 is a rare case of a molybdenum oxide/organic hybrid that acts as a stable solid catalyst for olefin epoxidation with tert-butyl hydroperoxide. The catalyst was effective for converting biobased olefins, namely fatty acid methyl esters (methyl oleate, methyl linoleate, methyl linolenate, and methyl ricinoleate) and the terpene limonene, leading predominantly to the corresponding epoxide products with yields in the range of 85–100% after 24 h at 70 °C. The versatility of catalyst 2 was shown by its effectiveness for the oxidation of sulfides into sulfoxides and sulfones, at 35 °C (quantitative yield of sulfoxide plus sulfone, at 24 h; sulfone yields in the range of 77–86%). To the best of our knowledge, 2 is the first molybdenum catalyst reported for methyl linolenate epoxidation, and the first of the family [MoO3(L)x] studied for methyl ricinoleate epoxidation.

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Teimouri, Abbas, Bahareh Najari, Alireza Najafi Chermahini, Hossein Salavati e Mahmoud Fazel-Najafabadi. "Characterization and catalytic properties of molybdenum oxide catalysts supported on ZrO2–γ-Al2O3 for ammoxidation of toluene". RSC Adv. 4, n.º 71 (2014): 37679–86. http://dx.doi.org/10.1039/c4ra07435a.

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Molybdenum oxide catalysts with MoO₃ loadings ranging from 6.6 to 25 wt% supported on ZrO₂–γ-Al₂O₃ (1 : 1 wt%) mixed oxide were prepared by a wet impregnation method.

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Zhang, Qiuyun, Xiaofang Liu, Tingting Yang, Quanlin Pu, Caiyan Yue, Shuya Zhang e Yutao Zhang. "Catalytic Transfer of Fructose to 5-Hydroxymethylfurfural over Bimetal Oxide Catalysts". International Journal of Chemical Engineering 2019 (1 de abril de 2019): 1–6. http://dx.doi.org/10.1155/2019/3890298.

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Direct conversion of fructose into 5-hydroxymethylfurfural (HMF) is achieved by using modified aluminum-molybdenum mixed oxide (S-AlMo) as solid acid catalysts. The synthesized catalyst was characterized by powder XRD, nitrogen adsorption-desorption isotherm, NH3-TPD, and SEM. As a result, the presence of strong acidity, mesostructures, and high surface area in the S-AlMo catalyst was confirmed by nitrogen adsorption-desorption isotherm and NH3-TPD studies. A study by optimizing the reaction conditions such as catalyst dosage, reaction temperature, and time has been performed. Under the optimal reaction conditions, HMF was obtained in a high yield of 49.8% by the dehydration of fructose. Moreover, the generality of the catalyst is also demonstrated by glucose and sucrose with moderate yields to HMF (24.9% from glucose; 27.6% from sucrose) again under mild conditions. After the reaction, the S-AlMo catalyst can be easily recovered and reused four times without significant loss of its catalytic activity.

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Aghayeva, K. X., e V. L. Baghiyev. "INVESTIGATION OF THE ISOMERIZATION REACTION OF BUTENE-1 TO BUTENES-2 ON BINARY TUNGSTEN-CONTAINING CATALYSTS". Chemical Problems 20, n.º 3 (2022): 256–63. http://dx.doi.org/10.32737/2221-8688-2022-3-256-263.

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The activity of tungsten-containing catalysts in the reaction of isomerization of butene-1 to butenes-2 was studied in the work. The results obtained showed that the ^ introduction of the second element into the composition of the tungsten oxide catalyst had a different effect on its activity in the butene-1 isomerization reaction. It was established that an increase in the amount of molybdenum in the composition of a binary tungsten-containing catalyst at low temperatures leads to a decrease in the degree of butene-1 isomerization while at high temperatures it leads to an increase in the rate of butene-1 isomerization. It found that the addition of titanium to the composition of the tungsten oxide catalyst leads to an increase in the butene-1 isomerization rate. When copper is added to the composition of the tungsten oxide catalyst, the total yield of butene-2 passes through a maximum, and on samples rich in copper, the isomerization of butene-1 practically does not occur. It revealed that the activity of binary tungsten oxide catalysts in the isomerization reaction of butene-1 to butenes-2 changes in the following order: Ti-W-O > Mo-W-O > Cu-WO.

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Widi, Restu Kartiko, e Sharifah Bee Abd Hamid. "Steam Influence and Effect of Oxidant Amount on Propane Oxidation over Multi Metal Oxide Catalyst Using High-Throughput Experiment". Indonesian Journal of Chemistry 18, n.º 2 (30 de maio de 2018): 229. http://dx.doi.org/10.22146/ijc.23959.

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The high-throughput experimentation technique was used to verify the testing conditions due to the effects of catalyst structure modifications and/or due to reaction parameter variation in parallel. In this paper, the design of experiment and catalytic results are discussed in the development of selective oxidation catalyst, to demonstrate the importance and versatility of such technology. It is used for the automated parallel testing of selective oxidation of propane to acrylic acid over some types of multi metal oxide catalysts. The catalysts used for performance test were Mo (molybdenum), cat-1 (unsupported Mo1V0.3Te0.23Nb0.125O), and cat-2 (supported Mo1V0.3Te0.23Nb0.125O). All catalysts were dried using spray drier. The effect of some reaction parameters, such as the amount of oxidant, presence of steam and reaction temperature was also investigated during the test. The configuration of the ‘nanoflow’ is shown to be suitable to screen catalytic performance. The results obtained gave very good reproducibility.

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Nguyen, Trung Thanh. "CO-OXIDATION REACTION ACTIVITY OF Pt CLUSTER CATALYSTS ON Ti0.9MO0.1O2 SUPPORT". Vietnam Journal of Science and Technology 54, n.º 4B (22 de março de 2018): 193. http://dx.doi.org/10.15625/2525-2518/54/4b/12041.

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Platinum-based heterogeneous catalysts are critical to many important commercial chemical processes. However, their efficiency is extremely low on a per metal atom basis, because only the surface active-site atoms are used. Catalysts with clusters of atom dispersions are thus highly desirable to increase atom efficiency, but making them is challenging. Here we report the synthesis of a catalyst that consists of isolated clusters of Pt atoms anchored to the surfaces of Molybdenum-doped titanium oxide nanocrystallites. This cluster-atom catalyst has extremely high atom efficiency and shows excellent stability and activity for CO oxidation. The result showed that the highest activity and stability of catalyst with 0.2 wt.% loading of Pt are observed. These could be due to the partially vacant 5d orbitals of the positively charged, high-valent Pt atoms.

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Silva, Adriano Lima da, Helder de Lucena Pereira, Herbet Bezerra Sales, Juliana Kelly Dionízio, Mary Cristina Ferreira Alves, Danyelle Garcia Guedes, Carlos Bruno Barreto Luna e Ana Cristina Figueiredo de Melo Costa. "Optimization of Biodiesel Production Process Using MoO3 Catalysts and Residual Oil: A Comprehensive Experimental 23 Study". Molecules 29, n.º 10 (20 de maio de 2024): 2404. http://dx.doi.org/10.3390/molecules29102404.

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The study aimed to utilize MoO3 catalysts, produced on a pilot scale via combustion reaction, to produce biodiesel from residual oil. Optimization of the process was conducted using a 23 experimental design. Structural characterization of the catalysts was performed through X-ray diffraction, fluorescence, Raman spectroscopy, and particle size distribution analyses. At the same time, thermal properties were examined via thermogravimetry and differential thermal analysis. Catalytic performance was assessed following process optimization. α-MoO3 exhibited a monophasic structure with orthorhombic phase, whereas α/h-MoO3 showed a biphasic structure. α-MoO3 had a larger crystallite size and higher crystallinity, with thermal stability observed up to certain temperatures. X-ray fluorescence confirmed molybdenum oxide predominance in the catalysts, with traces of iron oxide. Particle size distribution analyses revealed polymodal distributions attributed to structural differences. Both catalysts demonstrated activity under all conditions tested, with ester conversions ranging from 93% to 99%. The single-phase catalyst had a long life cycle and was reusable for six biodiesel production cycles. The experimental design proved to be predictive and significant, with the type of catalyst being the most influential variable. Optimal conditions included α-MoO3 catalyst, oil/alcohol ratio of 1/15, and a reaction time of 60 min, resulting in high biodiesel conversion rates and showcasing the viability of MoO3 catalysts in residual oil biodiesel production.

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Ochoa, Elba, Daniel Torres, José Luis Pinilla e Isabel Suelves. "Nanostructured Carbon Material Effect on the Synthesis of Carbon-Supported Molybdenum Carbide Catalysts for Guaiacol Hydrodeoxygenation". Energies 13, n.º 5 (5 de março de 2020): 1189. http://dx.doi.org/10.3390/en13051189.

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The impact of using different nanostructured carbon materials (carbon nanofibers, carbon nanotubes, graphene oxide and activated carbon) as a support for Mo2C-based catalysts on the hydrodeoxygenation (HDO) of guaiacol was studied. To optimise the catalyst preparation by carbothermal hydrogen reduction (CHR), a thermogravimetric study was conducted to select the optimum CHR temperature for each carbon material, considering both the crystal size of the resulting β-Mo2C particles and the extent of the support gasification. Subsequently, catalysts were prepared in a fixed bed reactor at the optimum temperature. Catalyst characterization evidenced the differences in the catalyst morphology as compared to those prepared in the thermogravimetric study. The HDO results demonstrated that the carbon nanofiber-based catalyst was the one with the best catalytic performance. This behaviour was attributed to the high thermal stability of this support, which prevented its gasification and promoted a good evolution of the crystal size of Mo species. This catalyst exhibited well-dispersed β-Mo2C nanoparticles of ca. 11 nm. On the contrary, the other supports suffered from severe gasification (60–70% wt. loss), which resulted in poorer HDO efficiency catalysts regardless of the β-Mo2C crystal size. This exhibited the importance of the carbon support stability in Mo2C-based catalysts prepared by CHR.

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Boyadjian, Cassia, e Leon Lefferts. "Promoting Li/MgO Catalyst with Molybdenum Oxide for Oxidative Conversion of n-Hexane". Catalysts 10, n.º 3 (23 de março de 2020): 354. http://dx.doi.org/10.3390/catal10030354.

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In this work, molybdena-promoted Li/MgO is studied as a catalyst for the oxidative conversion of n-hexane. The structure of the catalysts is investigated with X-ray Diffraction (XRD) and Raman spectroscopy. The MoO3/Li/MgO catalyst contains three types of molybdena-containing species, the presence of which depend on molybdena loading. At low Mo/Li ratios (i) isolated dispersed [MoO4]2− anionic species are observed. At high Mo/Li ratios, the formation of crystalline lithium molybdate phases such as (ii) monomeric Li2MoO4 and tentatively (iii) polymeric Li2Mo4O13 are concluded. The presence of these lithium molybdates diminishes the formation of Li2CO3 in the catalyst. Subsequently, the catalyst maintains high surface area and stability with time-on-stream during oxidative conversion. Molybdena loading as low as 0.5 wt % is sufficient to induce these improvements, maintaining the non-redox characteristics of the catalyst, whereas higher loadings enhance deep oxidation and oxidative dehydrogenation reactions. Promoting a Li/MgO catalyst with 0.5 wt % MoO3 is thus efficient for selective conversion of n-hexane to alkenes, giving alkene yield up to 24% as well as good stability.

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Sokolova, Yulia V., e Anton N. Chepikov. "OXIDATIVE ROASTING OF INDUSTRIAL SPENT CATALYSTS CO-Mo/Al2O3 HYDROPROCESSING WITH LIM". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, n.º 11 (27 de outubro de 2020): 57–64. http://dx.doi.org/10.6060/ivkkt.20206311.6256.

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The oxidative roasting of industrial spent catalyst Co-Mo/Al2O3 for the hydrotreatment of diesel fuel with lime in an air atmosphere was studied. Using the data of DTA, TG and X-ray phase analysis, it was found that during roasting, the sulfur and carbon oxides forms CaSO4 and CaCO3, and Mo is converted to calcium molybdate. Using the filtering fixed bed of reagents, the kinetics of roasting was studied. It was found that in the temperature range of 550 – 600 °C with air, supply rate of 3 l/min the process ends in 38 - 44 min for ground and non-ground catalyst. The optimal parameters (lime consumption, temperature, and time of roasting) of the absorption of sulfur oxides during roasting were determined. The degree of sulfur and carbon oxides adsorption is 96 and 36%, respectively. Separation of roasting products using unmilled spent catalyst is proposed into a small fraction (contains a mixture of CaSO4, CaCO3 and CaO) and a coarse (consists of Al2O3, CaMoO4, CoO) fractions, and their separate processing. It has been shown that in the separate processing of roast fractions by a sodium carbonate solution, it is possible to separately obtain alumina (catalyst base) with cobalt oxide, a molybdenum-containing solution, and also a mixture of sulfate, carbonate and oxide calcium. The used method of roasting the spent hydrotreating catalyst with lime will allow hazardous waste of hazard class 3-4 to be disposed of without hazardous waste gas costs. It allows one to obtain, during further processing, molybdenum and cobalt compounds, as well as finely divided alumina.

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Klienkov, Alexey V., Lyubov A. Petukhova e Alexander A. Petukhov. "The study of molybdenum-containing solutions by IR spectroscopy". Butlerov Communications 61, n.º 2 (29 de fevereiro de 2020): 103–7. http://dx.doi.org/10.37952/roi-jbc-01/20-61-2-103.

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Molybdenum compounds are widely used as catalysts for various chemical reactions, such as: oxidation, epoxidation, hydrogenation, reduction, etc. In particular, molybdenum compounds are used as a catalyst in the epoxidation of propylene with ethylbenzene hydroperoxide during the joint production of styrene and propylene oxide introduced into the industry as part of PJSC "Nizhnekamskneftekhim". We are working to verify the possibility of using glycol solutions, oxygen-containing inorganic compounds of molybdenum, such as molybdenum acid (MK), molybdenum anhydride (MA) and ammonium paramolybdate (PMA) as an epoxidation reaction catalyst. In the initial molybdenum compounds used to prepare the catalyst solutions, molybdenum is in the hexavalent state. The temperature treatment of these compounds in coordinating solvents, glycols, leads to their partial depolymerization and reduction to Mo(VI). Moreover, the more coordinating the solvent, the deeper these processes are flowed. There are reports in the literature on the study of various molybdenum compounds in aqueous media and crystalline state by IR spectroscopy and Raman scattering. It was found that the dissolution of MA, MK, and PMA in monoethylene glycol (MEG) is associated with the formation in the solution of compounds Mo(V), Mo(VI) of various molecular composition in the form of monomers, dimers, tetramers, and also in the form of the main components of hept- and octamers and higher molecular weight compounds. As the temperature rises, initially larger monomers of the octa- and hepta-form type transform into monomers of lower aggregation. All established patterns are analyzed by the example of PMA solutions in MEG.

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WAGNER, J. "Nanostructuring of binary molybdenum oxide catalysts for propene oxidation". Journal of Catalysis 225, n.º 1 (julho de 2004): 78–85. http://dx.doi.org/10.1016/j.jcat.2004.03.041.

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SHIMADA, H. "XAFS study of molybdenum oxide catalysts on various supports". Journal of Catalysis 138, n.º 2 (dezembro de 1992): 746–49. http://dx.doi.org/10.1016/0021-9517(92)90321-8.

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Kim, D. S., I. E. Wachs e K. Segawa. "Molecular Structures and Reactivity of Supported Molybdenum Oxide Catalysts". Journal of Catalysis 149, n.º 2 (outubro de 1994): 268–77. http://dx.doi.org/10.1006/jcat.1994.1295.

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Unnarkat, Ashish P., Tam Sridhar, Huanting Wang, Sanjay Mahajani e Akkihebbal K. Suresh. "Cobalt molybdenum oxide catalysts for selective oxidation of cyclohexane". AIChE Journal 62, n.º 12 (17 de junho de 2016): 4384–402. http://dx.doi.org/10.1002/aic.15335.

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Ragaini, Vittorio, Giovanni Matarrese, Nicola Giordano e Jan C. J. Bart. "Acidity and reactivity of some supported molybdenum oxide catalysts". Recueil des Travaux Chimiques des Pays-Bas 97, n.º 4 (2 de setembro de 2010): 97–104. http://dx.doi.org/10.1002/recl.19780970404.

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Hlatshwayo, Xolani Sibusiso, Morena S. Xaba, Matumuene Joe Ndolomingo, Ndzondelelo Bingwa e Reinout Meijboom. "The Efficient Recyclable Molybdenum- and Tungsten-Promoted Mesoporous ZrO2 Catalysts for Aminolysis of Epoxides". Catalysts 11, n.º 6 (25 de maio de 2021): 673. http://dx.doi.org/10.3390/catal11060673.

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In the present study, we report the synthesis and catalytic activity of tungsten- and molybdenum-promoted mesoporous metal oxides in the aminolysis of epoxides. The as-synthesized catalysts were fully characterized by a variety of techniques such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), temperature-programmed reduction (TPR) and desorption (TPD), nitrogen sorption measurements, powder X-ray diffraction (p-XRD), and thermogravimetric analysis (TGA). Amongst the two supports utilized, ZrO2 is a better support compared to SiO2. Furthermore, MoO3 proved to be a better dopant compared to its counterpart. Several parameters such as the variation of solvents, substrates, catalyst amounts, and stirring speed were investigated. It was observed that 450 rpm was the optimum stirring speed, with toluene as the best solvent and styrene oxide as the best substrate. Moreover, the optimum parameters afforded 98% conversion with 95% selectivity towards 2-phenyl-2-(phenylamino) ethanol and 5% towards 1-phenyl-2-(phenylamino) ethanol. Furthermore, 5%MoO3-ZrO2 catalyst demonstrated optimal performance and it exhibited excellent activity as well as great stability after being recycled 6 times.

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Sheng, Tao, Baobao Cao, Yong Zhang e Haitao Zhang. "New growth modes of molybdenum oxide layered 1D structures using alternative catalysts: transverse mode vs. axial mode". CrystEngComm 17, n.º 5 (2015): 1139–50. http://dx.doi.org/10.1039/c4ce01869a.

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Both transverse and axial growth modes were discovered in the CVD synthesis of molybdenum oxide (MoO₃) 1D structures using alkali metal based catalysts. A modified vapor–solid–solid (VSS) mechanism was proposed.

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Scholz, Juliane, Anke Walter e Thorsten Ressler. "Structural Investigations of Molybdenum Oxide Based Catalysts Supported on Nanostructured Magnesium Oxide". Zeitschrift für anorganische und allgemeine Chemie 636, n.º 11 (setembro de 2010): 2079. http://dx.doi.org/10.1002/zaac.201009060.

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Lindahl Christiansen, Troels, Emil T. S. Kjær, Anton Kovyakh, Morten L. Röderen, Martin Høj, Tom Vosch e Kirsten M. Ø. Jensen. "Structure analysis of supported disordered molybdenum oxides using pair distribution function analysis and automated cluster modelling". Journal of Applied Crystallography 53, n.º 1 (1 de fevereiro de 2020): 148–58. http://dx.doi.org/10.1107/s1600576719016832.

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Molybdenum oxides and sulfides on various low-cost high-surface-area supports are excellent catalysts for several industrially relevant reactions. The surface layer structure of these materials is, however, difficult to characterize due to small and disordered MoO x domains. Here, it is shown how X-ray total scattering can be applied to gain insights into the structure through differential pair distribution function (d-PDF) analysis, where the scattering signal from the support material is subtracted to obtain structural information on the supported structure. MoO x catalysts supported on alumina nanoparticles and on zeolites are investigated, and it is shown that the structure of the hydrated molybdenum oxide layer is closely related to that of disordered and polydisperse polyoxometalates. By analysing the PDFs with a large number of automatically generated cluster structures, which are constructed in an iterative manner from known polyoxometalate clusters, information is derived on the structural motifs in supported MoO x .

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Thrane, Joachim, Uffe V. Mentzel, Max Thorhauge, Martin Høj e Anker D. Jensen. "A Review and Experimental Revisit of Alternative Catalysts for Selective Oxidation of Methanol to Formaldehyde". Catalysts 11, n.º 11 (31 de outubro de 2021): 1329. http://dx.doi.org/10.3390/catal11111329.

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The selective oxidation of methanol to formaldehyde is a growing million-dollar industry, and has been commercial for close to a century. The Formox process, which is the largest production process today, utilizes an iron molybdate catalyst, which is highly selective, but has a short lifetime of 6 months due to volatilization of the active molybdenum oxide. Improvements of the process’s lifetime is, thus, desirable. This paper provides an overview of the efforts reported in the scientific literature to find alternative catalysts for the Formox process and critically assess these alternatives for their industrial potential. The catalysts can be grouped into three main categories: Mo containing, V containing, and those not containing Mo or V. Furthermore, selected interesting catalysts were synthesized, tested for their performance in the title reaction, and the results critically compared with previously published results. Lastly, an outlook on the progress for finding new catalytic materials is provided as well as suggestions for the future focus of Formox catalyst research.

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