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Lactic acid conversion into acrylic acid and other products over natural and synthetic zeolite catalysts: theoretical and experimental studies. Catal Today 2021. [DOI: 10.1016/j.cattod.2021.10.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Li Y, Wang R, Chen Z, Zhao X, Luo X, Wang L, Li Y, Teng F. Preparation of magnetic mesoporous silica from rice husk for aflatoxin B1 removal: Optimum process and adsorption mechanism. PLoS One 2020; 15:e0238837. [PMID: 32913353 PMCID: PMC7482997 DOI: 10.1371/journal.pone.0238837] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/25/2020] [Indexed: 11/19/2022] Open
Abstract
The liquid foodstuffs such as edible oil products remain a problem of excessive aflatoxin B1 (AFB1) content. This paper focused on the preparation of magnetic mesoporous silica (MMS) from rice husk ash for the removal of AFB1 in oil system. The MMS preparation process, adsorption conditions, structural characteristics, and adsorption mechanism were investigated. The optimum conditions for MMS preparation were pH 11.0 and 80°C for 24 h. The characterization results showed that magnetic particles were successfully embedded in the MMS and had high responsiveness to a magnetic field, which was advantageous for recyclability. The MMS had ordered uniform channels with a specific surface area of 730.98 m2/g and pore diameter of 2.43 nm. The optimum adsorption conditions were 2 h at 20°C. For AFB1 with an initial concentration of 0.2 μg/mL, the MMS adsorption capacity was 171.98 μg/g and the adsorption rate was 94.59%. The MMS adsorption isotherm fitted the Langmuir model well under the assumption of monolayer AFB1 adsorption with uniformly distributed adsorption sites on the MMS surface. The maximum amount of AFB1 adsorbed according to the Langmuir isotherm was 1118.69 μg/g. A quasi-second-order kinetic model gave a better fit to the process of AFB1 adsorption on MMS. The values of ΔH (-19.17 kJ/mol) and ΔG (-34.09, -34.61, and -35.15 kJ/mol at 283, 293, and 303 K, respectively) were negative, indicating that AFB1 adsorption on MMS was a spontaneous exothermic process. The results indicated that MMS was a promising material for AFB1 removal in oil system, and this study will serve as a guide for practical MMS applications.
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Affiliation(s)
- Yanan Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Ren Wang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Zhengxing Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Xiuping Zhao
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Xiaohu Luo
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Li Wang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Yongfu Li
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Fei Teng
- School of Food Science and Technology, Jiangnan University, Wuxi, China
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Şahin V, Karabakan A. Molecular level nucleation mechanisms of hierarchical MFI and MOR zeolite structures via non-stochastic pathways. NANOSCALE 2020; 12:16292-16304. [PMID: 32720656 DOI: 10.1039/d0nr03334k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Understanding the chemical mechanism of crystal nucleation at the molecular level is crucial for the design of architectural structures of valuable materials in the future. In this study, it has been revealed that amorphous silicate precursors, which play a role in the nucleation processes of zeolitic frameworks, can be regularly fragmented in mass spectroscopy due to the hydroxyl functional groups in their molecular structures. In this way, by using the mass spectra acquired from LDI-TOF MS, the systematic evolution stages of a common 1D precursor converting to the 3D unit cells of MFI and MOR zeolite structures observed in the same reaction medium were constructed through a nucleation mechanism at the molecular level for the first time. Here we show a novel nucleation pathway that does not occur via stochastic assembly of atoms or distinct building blocks by molecular recognition. Each of the proposed nucleation mechanisms of these different frameworks carrying structural similarities is from different combinations of sequential self-attaching intramolecular covalent couplings of identical origin precursors. The dynamic molecular structure capable of forming finite building units of target frameworks during the nucleation process of this precursor, which is the polymerized form of simple 6-membered siloxane chains, has been arranged around structure directing agents before a hydrothermal reaction.
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Affiliation(s)
- Volkan Şahin
- Department of Chemistry Hacettepe University, Ankara 06800, Turkey.
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Sobuś N, Michorczyk B, Piotrowski M, Kuterasiński Ł, Chlebda DK, Łojewska J, Jędrzejczyk RJ, Jodłowski P, Kuśtrowski P, Czekaj I. Design of Co, Cu and Fe–BEA Zeolite Catalysts for Selective Conversion of Lactic Acid into Acrylic Acid. Catal Letters 2019. [DOI: 10.1007/s10562-019-02883-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rohling R, Szyja BM, Hensen EJM. Insight into the Formation of Nanostructured MFI Sheets and MEL Needles Driven by Molecular Recognition. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:5326-5335. [PMID: 30873254 PMCID: PMC6410615 DOI: 10.1021/acs.jpcc.8b08251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/03/2019] [Indexed: 06/09/2023]
Abstract
Mesoporous and nanostructured zeolite-based catalysts experience prolonged lifetimes due to increased mass transfer and reduced micropore obstruction by coke formation as compared to their bulky microporous counterparts. Diquaternary ammonium structure-directing agents (SDAs) can be used to synthesize hierarchical MFI sheet-like and MEL needle-like zeolites. An explanation of the underlying molecular-level details of the synthesis of these nanostructured zeolites is presented on the basis of non-covalent interactions between the template and zeolite surfaces as well as silicate oligomers studied by means of classical molecular dynamics. Use was made of Si11 and Si33 silicate oligomers that contain structural features of the framework to be formed as originally proposed by the Leuven group. Molecular recognition is driven by a combination of strong electrostatic and weaker dispersion interactions. An analysis of the early stage of zeolite formation is necessary, as the template adsorption energies in the fully formed zeolite crystals cannot explain the preferential growth of the MFI sheets or MEL needles. Specifically, it is found that the differences in dispersion interactions between the SDA alkyl chains and the silicate oligomers are decisive in the formation of particular zeolite structures.
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Affiliation(s)
- Roderigh
Y. Rohling
- Inorganic
Materials Chemistry, Department of Chemical Engineering and Catalysis, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
| | - Bartłomiej M. Szyja
- Inorganic
Materials Chemistry, Department of Chemical Engineering and Catalysis, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
- Division
of Fuels Chemistry and Technology, Faculty of Chemistry, Wrocław University of Science and Technology, Gdańska 7/9, 50-344 Wrocław, Poland
| | - Emiel J. M. Hensen
- Inorganic
Materials Chemistry, Department of Chemical Engineering and Catalysis, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
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Zhu X, Goesten MG, Koekkoek AJJ, Mezari B, Kosinov N, Filonenko G, Friedrich H, Rohling R, Szyja BM, Gascon J, Kapteijn F, Hensen EJM. Establishing hierarchy: the chain of events leading to the formation of silicalite-1 nanosheets. Chem Sci 2016; 7:6506-6513. [PMID: 28616128 PMCID: PMC5458680 DOI: 10.1039/c6sc01295g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/22/2016] [Indexed: 11/29/2022] Open
Abstract
In applying a multi-scale spectroscopic and computational approach, we demonstrate that the synthesis of stacked zeolite silicalite-1 nanosheets, in the presence of a long-tail diquaternary ammonium salt surfactant, proceeds through a pre-organised phase in the condensed state. In situ small-angle X-ray scattering, coupled to paracrystalline theory, and backed by electron microscopy, shows that this phase establishes its meso-scale order within the first five hours of hydrothermal synthesis. Quasi in situ vibrational and solid-state NMR spectroscopy reveal that this meso-shaped architecture already contains some elementary zeolitic features. The key to this coupled organisation at both micro- and meso-scale, is a structure-directing agent that is ambifunctional in shaping silica at the meso-scale whilst involved in molecular recognition at the micro-scale. The latter feature is particularly important and requires the structure-directing agent to reside within the silica matrix already at early stages of the synthesis. From here, molecular recognition directs stabilization of precursor species and their specific embedding into a lattice, as shown by force-field molecular dynamics calculations. These calculations, in line with experiment, further show how it is possible to subtly tune both the zeolite topology and aspect ratio of the condensating crystals, by modifying the headgroup of the structure-directing agent.
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Affiliation(s)
- Xiaochun Zhu
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Maarten G Goesten
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Arjan J J Koekkoek
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Brahim Mezari
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Nikolay Kosinov
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Georgy Filonenko
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Heiner Friedrich
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Laboratory of Materials and Interface Chemistry and TU/e Center of Multiscale Electron Microscopy , Netherlands
| | - Roderigh Rohling
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Bartłomiej M Szyja
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
| | - Jorge Gascon
- Delft University of Technology , Chemical Engineering , Netherlands
| | - Freek Kapteijn
- Delft University of Technology , Chemical Engineering , Netherlands
| | - Emiel J M Hensen
- Eindhoven University of Technology , Department of Chemical Engineering and Chemistry , Schuit Institute of Catalysis , Inorganic Materials Chemistry , Netherlands .
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Grand J, Awala H, Mintova S. Mechanism of zeolites crystal growth: new findings and open questions. CrystEngComm 2016. [DOI: 10.1039/c5ce02286j] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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