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Schumacher L, Radtke M, Welzenbach J, Hess C. Unraveling surface and bulk dynamics of iron(III) molybdate during oxidative dehydrogenation using operando and transient spectroscopies. Commun Chem 2023; 6:230. [PMID: 37884607 PMCID: PMC10603085 DOI: 10.1038/s42004-023-01028-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023] Open
Abstract
Iron(III) molybdate (Fe2(MoO4)3) is a commercial catalyst for the oxidative dehydrogenation (ODH) of methanol, but it has recently been shown to be relevant for other substrates as well. Despite its commercial use, a detailed mechanistic understanding of Fe2(MoO4)3 catalysts at the surface and in the bulk has been lacking, largely hampered by the lack of suitable spectroscopic methods, directly applicable under reaction conditions. Using propane ODH as an example, we highlight the potential of operando Raman and impedance spectroscopy combined with transient IR spectroscopy, to identify surface active sites and monitor the hydrogen transfer and oxygen dynamics. By comparison with the behavior of reference compounds (MoO3, MoOx/Fe2O3) a mechanistic model is proposed. The presence of iron greatly influences the reactivity behavior via oxygen diffusion but is moderated in its oxidative capacity by surface MoOx. Our approach directly elucidates fundamental properties of Fe2(MoO4)3 of general importance to selective oxidation catalysis.
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Affiliation(s)
- Leon Schumacher
- Technical University of Darmstadt, Department of Chemistry, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Peter-Grünberg-Str. 8, 64287, Darmstadt, Germany
| | - Mariusz Radtke
- Technical University of Darmstadt, Department of Chemistry, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Peter-Grünberg-Str. 8, 64287, Darmstadt, Germany
| | - Jan Welzenbach
- Technical University of Darmstadt, Department of Chemistry, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Peter-Grünberg-Str. 8, 64287, Darmstadt, Germany
| | - Christian Hess
- Technical University of Darmstadt, Department of Chemistry, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Peter-Grünberg-Str. 8, 64287, Darmstadt, Germany.
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2
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Mahdi HI, Ramlee NN, Santos DHDS, Giannakoudakis DA, de Oliveira LH, Selvasembian R, Azelee NIW, Bazargan A, Meili L. Formaldehyde production using methanol and heterogeneous solid catalysts: A comprehensive review. MOLECULAR CATALYSIS 2023. [DOI: 10.1016/j.mcat.2023.112944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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3
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Abstract
Controlled growth of well-oriented metal-organic framework nanoarrays on requisite surfaces is of prominent significance for a broad range of applications such as catalysis, sensing, optics and electronics. Herein, we develop a highly flexible soft nanobrush-directed synthesis approach for precise in situ fabrication of MOF nanoarrays on diverse substrates. The soft nanobrushes are constructed via surface-initiated living crystallization-driven self-assembly and their active poly(2-vinylpyridine) corona captures abundant metal cations through coordination interactions. This allows the rapid heterogeneous growth of MOF nanoparticles and the subsequent formation of MIL-100 (Fe), HKUST-1 and CUT-8 (Cu) nanoarrays with tailored heights of 220~1100 nm on silicon wafer, Ni foam and ceramic tube. Auxiliary functional components including metal oxygen clusters and precious metal nanoparticles can be readily incorporated to finely fabricate hybrid structures with synergistic features. Remarkably, the MIL-100 (Fe) nanoarrays doped with Keggin H3PMo10V2O40 dramatically boost formaldehyde selectivity up to 92.8% in catalytic oxidation of methanol. Moreover, the HKUST-1 nanoarrays decorated with Pt nanoparticles show exceptional sensitivity to H2S with a ppb-level detection limit. Tailored growth of MOFs is of great interest for a broad range of applications. Here authors present the use of soft nanobrushes to direct the growth of MOF nanoarrays on requisite substrates, which simultaneously allows the loading of auxiliary functional species for advanced catalysis and sensing applications.
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4
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Mu J, Liu J, Qin J, Li X, Liu B. Unveiling remarkable resistance to Pb poisoning over an Fe–Mo catalyst for low-temperature NH 3-SCR: poison transforms into a promoter. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00630h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A heavy metal-resistant NOx catalytic reduction Fe–Mo catalyst was developed and a novel intrinsic activity enhancement mechanism by Pb species was originally demonstrated.
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Affiliation(s)
- Jincheng Mu
- College of Resource and Environmental Engineering, Guizhou University, Guizhou Karst Environmental Ecosystems Observation and Research Station, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, 550025, China
| | - Jie Liu
- Department of Environmental Science & Engineering, North China Electric Power University, Baoding, 071003, China
| | - Jiangzhou Qin
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China
| | - Xinyong Li
- State Key Laboratory of Fine Chemicals, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Baojun Liu
- College of Resource and Environmental Engineering, Guizhou University, Guizhou Karst Environmental Ecosystems Observation and Research Station, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, 550025, China
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5
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Thrane J, Falholt Elvebakken C, Juelsholt M, Lindahl Christiansen T, Jensen KMØ, Pilsgaard Hansen L, Fahl Lundegaard L, Vie Mentzel U, Thorhauge M, Degn Jensen A, Høj M. Highly Stable Apatite Supported Molybdenum Oxide Catalysts for Selective Oxidation of Methanol to Formaldehyde: Structure, Activity and Stability. ChemCatChem 2021. [DOI: 10.1002/cctc.202101220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Joachim Thrane
- Department of Chemical and Biochemical Engineering Technical University of Denmark (DTU) Søltofts Plads 228 A DK-2800 Kgs. Lyngby Denmark
| | - Christopher Falholt Elvebakken
- Department of Chemical and Biochemical Engineering Technical University of Denmark (DTU) Søltofts Plads 228 A DK-2800 Kgs. Lyngby Denmark
| | - Mikkel Juelsholt
- Department of Chemistry University of Copenhagen (KU) Universitetsparken 5 DK-2100 København Ø Denmark
| | | | - Kirsten M. Ø. Jensen
- Department of Chemistry University of Copenhagen (KU) Universitetsparken 5 DK-2100 København Ø Denmark
| | | | | | - Uffe Vie Mentzel
- Haldor Topsøe A/S Haldor Topsøes Allé 1 DK-2800 Kgs. Lyngby Denmark
| | - Max Thorhauge
- Haldor Topsøe A/S Haldor Topsøes Allé 1 DK-2800 Kgs. Lyngby Denmark
| | - Anker Degn Jensen
- Department of Chemical and Biochemical Engineering Technical University of Denmark (DTU) Søltofts Plads 228 A DK-2800 Kgs. Lyngby Denmark
| | - Martin Høj
- Department of Chemical and Biochemical Engineering Technical University of Denmark (DTU) Søltofts Plads 228 A DK-2800 Kgs. Lyngby Denmark
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6
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A Review and Experimental Revisit of Alternative Catalysts for Selective Oxidation of Methanol to Formaldehyde. Catalysts 2021. [DOI: 10.3390/catal11111329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
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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7
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Modified iron-molybdate catalysts with various metal oxides by a mechanochemical method: enhanced formaldehyde yield in methanol partial oxidation. Front Chem Sci Eng 2021. [DOI: 10.1007/s11705-020-2008-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Methanol to Formaldehyde: An Overview of Surface Studies and Performance of an Iron Molybdate Catalyst. Catalysts 2021. [DOI: 10.3390/catal11080893] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Formaldehyde is a primary chemical in the manufacturing of various consumer products. It is synthesized via partial oxidation of methanol using a mixed oxide iron molybdate catalyst (Fe2(MoO4)3–MoO3). This is one of the standard energy-efficient processes. The mixed oxide iron molybdate catalyst is an attractive commercial catalyst for converting methanol to formaldehyde. However, a detailed phase analysis of each oxide phase and a complete understanding of the catalyst formulation and deactivation studies is required. It is crucial to correctly formulate each oxide phase and influence the synthesis methods precisely. A better tradeoff between support and catalyst and oxygen revival on the catalyst surface is vital to enhance the catalyst’s selectivity, stability, and lifetime. This review presents recent advances on iron molybdate’s catalytic behaviour for formaldehyde production—a deep recognition of the catalyst and its critical role in the processes are highlighted. Finally, the conclusion and prospects are presented at the end.
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Sprenger P, Stehle M, Gaur A, Weiß J, Brueckner D, Zhang Y, Garrevoet J, Suuronen J, Thomann M, Fischer A, Grunwaldt J, Sheppard TL. Chemical Imaging of Mixed Metal Oxide Catalysts for Propylene Oxidation: From Model Binary Systems to Complex Multicomponent Systems. ChemCatChem 2021. [DOI: 10.1002/cctc.202100054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Paul Sprenger
- Institute for Chemical Technology and Polymer Chemistry Karlsruhe Institute of Technology Karlsruhe 76131 Germany
| | - Matthias Stehle
- Institute for Chemical Technology and Polymer Chemistry Karlsruhe Institute of Technology Karlsruhe 76131 Germany
| | - Abhijeet Gaur
- Institute for Chemical Technology and Polymer Chemistry Karlsruhe Institute of Technology Karlsruhe 76131 Germany
- Institute of Catalysis Research and Technology Karlsruhe Institute of Technology Eggenstein-Leopoldshafen 76344 Germany
| | - Jana Weiß
- Leibniz Institute for Catalysis (LIKAT) Rostock 18059 Germany
| | - Dennis Brueckner
- Deutsches Elektronen-Synchrotron DESY Hamburg 22607 Germany
- Faculty of Chemistry and Biochemistry Ruhr University Bochum Bochum 44801 Germany
- Department Physik Universität Hamburg Hamburg 22761 Germany
| | - Yi Zhang
- Deutsches Elektronen-Synchrotron DESY Hamburg 22607 Germany
| | - Jan Garrevoet
- Deutsches Elektronen-Synchrotron DESY Hamburg 22607 Germany
| | - Jussi‐Petteri Suuronen
- ESRF - The European Synchrotron Grenoble 38000 France
- Current Address: Xploraytion GmbH Berlin 10625 Germany
| | | | | | - Jan‐Dierk Grunwaldt
- Institute for Chemical Technology and Polymer Chemistry Karlsruhe Institute of Technology Karlsruhe 76131 Germany
- Institute of Catalysis Research and Technology Karlsruhe Institute of Technology Eggenstein-Leopoldshafen 76344 Germany
| | - Thomas L. Sheppard
- Institute for Chemical Technology and Polymer Chemistry Karlsruhe Institute of Technology Karlsruhe 76131 Germany
- Institute of Catalysis Research and Technology Karlsruhe Institute of Technology Eggenstein-Leopoldshafen 76344 Germany
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10
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Thrane J, Mentzel UV, Thorhauge M, Høj M, Jensen AD. Hydroxyapatite supported molybdenum oxide catalyst for selective oxidation of methanol to formaldehyde: studies of industrial sized catalyst pellets. Catal Sci Technol 2021. [DOI: 10.1039/d0cy01931c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Promising alternative catalysts for the Formox process as industrial sized pellets and the influence of pellet density on catalyst performance.
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Affiliation(s)
- Joachim Thrane
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- DK-2800 Kgs. Lyngby
- Denmark
| | | | | | - Martin Høj
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- DK-2800 Kgs. Lyngby
- Denmark
| | - Anker Degn Jensen
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- DK-2800 Kgs. Lyngby
- Denmark
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11
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Hess C. New advances in using Raman spectroscopy for the characterization of catalysts and catalytic reactions. Chem Soc Rev 2021; 50:3519-3564. [PMID: 33501926 DOI: 10.1039/d0cs01059f] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Gaining insight into the mode of operation of heterogeneous catalysts is of great scientific and economic interest. Raman spectroscopy has proven its potential as a powerful vibrational spectroscopic technique for a fundamental and molecular-level characterization of catalysts and catalytic reactions. Raman spectra provide important insight into reaction mechanisms by revealing specific information on the catalysts' (defect) structure in the bulk and at the surface, as well as the presence of adsorbates and reaction intermediates. Modern Raman instrumentation based on single-stage spectrometers allows high throughput and versatility in design of in situ/operando cells to study working catalysts. This review highlights major advances in the use of Raman spectroscopy for the characterization of heterogeneous catalysts made during the past decade, including the development of new methods and potential directions of research for applying Raman spectroscopy to working catalysts. The main focus will be on gas-solid catalytic reactions, but (photo)catalytic reactions in the liquid phase will be touched on if it appears appropriate. The discussion begins with the main instrumentation now available for applying vibrational Raman spectroscopy to catalysis research, including in situ/operando cells for studying gas-solid catalytic processes. The focus then moves to the different types of information available from Raman spectra in the bulk and on the surface of solid catalysts, including adsorbates and surface depositions, as well as the use of theoretical calculations to facilitate band assignments and to describe (resonance) Raman effects. This is followed by a presentation of major developments in enhancing the Raman signal of heterogeneous catalysts by use of UV resonance Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), and shell-isolated nanoparticle surface-enhanced Raman spectroscopy (SHINERS). The application of time-resolved Raman studies to structural and kinetic characterization is then discussed. Finally, recent developments in spatially resolved Raman analysis of catalysts and catalytic processes are presented, including the use of coherent anti-Stokes Raman spectroscopy (CARS) and tip-enhanced Raman spectroscopy (TERS). The review concludes with an outlook on potential future developments and applications of Raman spectroscopy in heterogeneous catalysis.
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Affiliation(s)
- Christian Hess
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, 64287, Darmstadt, Germany.
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12
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Kots PA, Artsiusheuski MA, Grigoriev YV, Ivanova II. One-Step Butadiene Synthesis via Gas-Phase Prins Condensation of Propylene with Formaldehyde over Heteropolyacid Catalysts. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03282] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pavel A. Kots
- Department of Chemistry, Lomonosov Moscow State University, Leninsky Gory 1, bld. 3, 119991 Moscow, Russia
| | - Mikalai A. Artsiusheuski
- Department of Chemistry, Lomonosov Moscow State University, Leninsky Gory 1, bld. 3, 119991 Moscow, Russia
| | - Yuriy V. Grigoriev
- National Research Center ≪Kurchatov Institute≫, Kurchatov Square, 1, 123098 Moscow, Russia
- Shubnikov Institute of Crystallography of Federal Scientific Research Centre ≪Crystallography and Photonics≫ RAS, Lenenskiy prosp., bld. 59, 119333 Moscow, Russia
| | - Irina I. Ivanova
- Department of Chemistry, Lomonosov Moscow State University, Leninsky Gory 1, bld. 3, 119991 Moscow, Russia
- A.V. Topchiev Institute of Petrochemical Synthesis, Leninskiy prosp., bld. 29, 117912 Moscow, Russia
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13
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Arumugam B, Muthukutty B, Chen SM, Kannan Ramaraj S, Vinoth Kumar J, Nagarajan ER. Ultrasonication-aided synthesis of nanoplates-like iron molybdate: Fabricated over glassy carbon electrode as an modified electrode for the selective determination of first generation antihistamine drug promethazine hydrochloride. ULTRASONICS SONOCHEMISTRY 2020; 66:104977. [PMID: 32315841 DOI: 10.1016/j.ultsonch.2020.104977] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/28/2019] [Accepted: 01/16/2020] [Indexed: 05/21/2023]
Abstract
The innovation of novel and proficient nanostructured materials for the precise level determination of pharmaceuticals in biological fluids is quite crucial to the researchers. With this in mind, we synthesized iron molybdate nanoplates (Fe2(MoO4)3; FeMo NPs) via simple ultrasonic-assisted technique (70 kHz with a power of 100 W). The FeMo NPs were used as the efficient electrocatalyst for electrochemical oxidation of first-generation antihistamine drug- Promethazine hydrochloride (PMH). The as-synthesized FeMo NPs were characterized and confirmed by various characterization techniques such as XRD, Raman, FT-IR, FE-SEM, EDX and Elemental mapping analysis and electron impedance spectroscopy (EIS). In addition, the electrochemical characteristic features of FeMo NPs were scrutinized by electrochemical techniques like cyclic voltammetry (CV) and differential pulse voltammetry technique (DPV). Interestingly, the developed FeMo NPs modified glassy carbon electrode (FeMo NPs/GCE) discloses higher peak current with lesser anodic potential on comparing to bare GCE including wider linear range (0.01-68.65 µM), lower detection limit (0.01 µM) and greater sensitivity (0.97 µAµM-1cm-2). Moreover, the as-synthesized FeMo NPs applied for selectivity, reproducibility, repeatability and storage ability to investigate the practical viability. In the presence of interfering species like cationic, anionic and biological samples, the oxidation peak current response doesn't cause any variation results disclose good selectivity towards the detection of PMH. Additionally, the practical feasibility of the FeMo NPs/GCE was tested by real samples like, commercial tablet (Phenergan 25 mg Tablets) and lake water samples which give satisfactory recovery results. All the above consequences made clear that the proposed sensor FeMo NPs/GCE exhibits excellent electrochemical behavior for electrochemical determination towards oxidation of antihistamine drug PMH.
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Affiliation(s)
- Balamurugan Arumugam
- PG & Research Department of Chemistry, Thiagarajar College, Madurai 09, Tamil Nadu, India
| | - Balamurugan Muthukutty
- Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC
| | - Shen-Ming Chen
- Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
| | - Sayee Kannan Ramaraj
- PG & Research Department of Chemistry, Thiagarajar College, Madurai 09, Tamil Nadu, India.
| | - Jeyaraj Vinoth Kumar
- Department of Chemistry, Nanomaterials Laboratory, International Research Center, Kalasalingam Academy of Research and Education, Krishnankoil, Tamil Nadu 626 126, India
| | - E R Nagarajan
- Department of Chemistry, Nanomaterials Laboratory, International Research Center, Kalasalingam Academy of Research and Education, Krishnankoil, Tamil Nadu 626 126, India
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14
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Kong L, Xu S, Liu X, Liu C, Zhang D, Zhao L. Effects of iron precursors on the structure and catalytic performance of iron molybdate prepared by mechanochemical route for methanol to formaldehyde. Chin J Chem Eng 2020. [DOI: 10.1016/j.cjche.2020.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Effect of Mo Dispersion on the Catalytic Properties and Stability of Mo-Fe Catalysts for the Partial Oxidation of Methanol. Molecules 2020; 25:molecules25102410. [PMID: 32455830 PMCID: PMC7287743 DOI: 10.3390/molecules25102410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 11/17/2022] Open
Abstract
Mo-Fe catalysts with different Mo dispersions were synthesized with fast (Cat-FS, 600 r·min-1) or slow stirring speed (Cat-SS, 30 r·min-1) by the coprecipitation method. Improving the stirring speed strengthened the mixing of the solution and increased the dispersion of particles in the catalyst, which exhibited favorable activity and selectivity. The byproduct (dimethyl ether (DME)) selectivity increased from 2.3% to 2.8% with Cat-SS, while it remained unchanged with Cat-FS in a stability test. The aggregation of particles and thin Mo-enriched surface layer decreased the catalyst surface area and slowed down the reoxidation of reduced active sites with Cat-SS, leaving more oxygen vacancies which promoted the formation of DME by the nonoxidative channel.
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Alkali Earth Metal Molybdates as Catalysts for the Selective Oxidation of Methanol to Formaldehyde—Selectivity, Activity, and Stability. Catalysts 2020. [DOI: 10.3390/catal10010082] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
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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Gaur A, Stehle M, Raun KV, Thrane J, Jensen AD, Grunwaldt JD, Høj M. Structural dynamics of an iron molybdate catalyst under redox cycling conditions studied with in situ multi edge XAS and XRD. Phys Chem Chem Phys 2020; 22:11713-11723. [DOI: 10.1039/d0cp01506g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Combination of in situ multi-edge X-ray absorption spectroscopy at the Mo K- and Fe K-edges in combination with X-ray diffraction successfully uncovered structural dynamics and phase transformations of an iron molybdate catalyst during redox cycling.
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Affiliation(s)
- Abhijeet Gaur
- Institute for Chemical Technology and Polymer Chemistry
- Karlsruhe Institute of Technology (KIT)
- Karlsruhe
- Germany
- Institute of Catalysis Research and Technology
| | - Matthias Stehle
- Institute for Chemical Technology and Polymer Chemistry
- Karlsruhe Institute of Technology (KIT)
- Karlsruhe
- Germany
| | - Kristian Viegaard Raun
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- Kgs. Lyngby
- Denmark
| | - Joachim Thrane
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- Kgs. Lyngby
- Denmark
| | - Anker Degn Jensen
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- Kgs. Lyngby
- Denmark
| | - Jan-Dierk Grunwaldt
- Institute for Chemical Technology and Polymer Chemistry
- Karlsruhe Institute of Technology (KIT)
- Karlsruhe
- Germany
- Institute of Catalysis Research and Technology
| | - Martin Høj
- Department of Chemical and Biochemical Engineering
- Technical University of Denmark (DTU)
- Kgs. Lyngby
- Denmark
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18
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Zhang S, Han M. Effect of synthesis pH on the structure and catalytic properties of FeMo catalysts. RSC Adv 2019; 9:41720-41728. [PMID: 35541632 PMCID: PMC9076469 DOI: 10.1039/c9ra07202k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 12/10/2019] [Indexed: 11/21/2022] Open
Abstract
The effect of pH on polynuclear molybdenum species (isopolymolybdates) synthesis was investigated by Raman spectroscopy. As the pH decreased from 6.0 to 1.0, the main isopolymolybdates changed from MoO4 2- to Mo7O24 6- to Mo8O24 6- to Mo36O116 8-. They began to aggregate and their solubility decreased with decreasing pH. The FeMo catalysts comprised particle- and plate-like structures, which were Fe2(MoO4)3 and MoO3, respectively. When a low pH value was used in the catalyst preparation, there was severe aggregation of the particles which have a high Mo/Fe mole ratio and Mo enrichment on the surface layer, which decreased the activity and selectivity of the FeMo catalyst.
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Affiliation(s)
- Shuai Zhang
- Department of Chemical Engineering, Beijing Key Laboratory of Green Reaction Engineering and Technology, Tsinghua University Beijing 100084 China
| | - Minghan Han
- Department of Chemical Engineering, Beijing Key Laboratory of Green Reaction Engineering and Technology, Tsinghua University Beijing 100084 China
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19
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Stability of Iron-Molybdate Catalysts for Selective Oxidation of Methanol to Formaldehyde: Influence of Preparation Method. Catal Letters 2019. [DOI: 10.1007/s10562-019-03034-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Methanol oxidation over shell-core MO /Fe2O3 (M = Mo, V, Nb) catalysts. CHINESE JOURNAL OF CATALYSIS 2019. [DOI: 10.1016/s1872-2067(19)63350-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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21
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Gaur A, Schumann M, Raun KV, Stehle M, Beato P, Jensen AD, Grunwaldt J, Høj M. Operando
XAS/XRD and Raman Spectroscopic Study of Structural Changes of the Iron Molybdate Catalyst during Selective Oxidation of Methanol. ChemCatChem 2019. [DOI: 10.1002/cctc.201901025] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Abhijeet Gaur
- Institute for Chemical Technology and Polymer ChemistryKarlsruhe Institute of Technology (KIT) D-76131 Karlsruhe Germany
- Institute of Catalysis Research and TechnologyKarlsruhe Institute of Technology (KIT) D-76344 Eggenstein-Leopoldshafen Germany
| | - Max Schumann
- Institute for Chemical Technology and Polymer ChemistryKarlsruhe Institute of Technology (KIT) D-76131 Karlsruhe Germany
- Department of Chemical and Biochemical EngineeringTechnical University of Denmark (DTU) DK-2800 Kgs. Lyngby Denmark
| | - Kristian Viegaard Raun
- Department of Chemical and Biochemical EngineeringTechnical University of Denmark (DTU) DK-2800 Kgs. Lyngby Denmark
| | - Matthias Stehle
- Institute for Chemical Technology and Polymer ChemistryKarlsruhe Institute of Technology (KIT) D-76131 Karlsruhe Germany
| | - Pablo Beato
- Haldor Topsøe A/S DK-2800 Kgs. Lyngby Denmark
| | - Anker Degn Jensen
- Department of Chemical and Biochemical EngineeringTechnical University of Denmark (DTU) DK-2800 Kgs. Lyngby Denmark
| | - Jan‐Dierk Grunwaldt
- Institute for Chemical Technology and Polymer ChemistryKarlsruhe Institute of Technology (KIT) D-76131 Karlsruhe Germany
- Institute of Catalysis Research and TechnologyKarlsruhe Institute of Technology (KIT) D-76344 Eggenstein-Leopoldshafen Germany
| | - Martin Høj
- Department of Chemical and Biochemical EngineeringTechnical University of Denmark (DTU) DK-2800 Kgs. Lyngby Denmark
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Raun KV, Thorhauge M, Høj M, Jensen AD. Modeling of molybdenum transport and pressure drop increase in fixed bed reactors used for selective oxidation of methanol to formaldehyde using iron molybdate catalysts. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.03.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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