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Horváth T, Kecskés K, Jordán Csábrádiné A, Szőri-Dorogházi E, Viskolcz B, Szőri M. Searching for the Achilles' Heel of Urethane Linkage-An Energetic Perspective. Polymers (Basel) 2024; 16:1126. [PMID: 38675045 PMCID: PMC11053941 DOI: 10.3390/polym16081126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/21/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
A sudden increase in polyurethane (PU) production necessitates viable recycling methods for the waste generated. PU is one of the most important plastic materials with a wide range of applications; however, the stability of the urethane linkage is a major issue in chemical recycling. In this work, termination reactions of a model urethane molecule, namely methyl N-phenyl carbamate (MPCate), are investigated using G3MP2B3 composite quantum chemical method. Our main goal was to gain insights into the energetic profile of urethane bond termination and find an applicable chemical recycling method. Hydrogenation, hydrolysis, methanolysis, peroxidation, glycolysis, ammonolysis, reduction with methylamine and termination by dimethyl phosphite were explored in both gas and condensed phases. Out of these chemicals, degradation by H2, H2O2 and CH3NH2 revealed promising results with lower activation barriers and exergonic pathways, especially in water solvation. Implementing these effective PU recycling methods can also have significant economic benefits since the obtained products from the reactions are industrially relevant substances. For example, aniline and dimethyl carbonate could be reusable in polymer technologies serving as potential methods for circular economy. As further potential transformations, several ionizations of MPCate were also examined including electron capture and detachment, protonation/deprotonation and reaction with OH-. Alkaline digestion against the model urethane MPCate was found to be promising due to the relatively low activation energy. In an ideal case, the transformation of the urethane bond could be an enzymatic process; therefore, potential enzymes, such as lipoxygenase, were also considered for the catalysis of peroxidation, and lipases for methanolysis.
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Affiliation(s)
- Tamás Horváth
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Karina Kecskés
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Anikó Jordán Csábrádiné
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Emma Szőri-Dorogházi
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Béla Viskolcz
- Higher Education and Industrial Cooperation Centre, University of Miskolc, H-3515 Miskolc, Hungary;
| | - Milán Szőri
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
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Sands KN, Burman AL, Ansah-Asamoah E, Back TG. Chemistry Related to the Catalytic Cycle of the Antioxidant Ebselen. Molecules 2023; 28:molecules28093732. [PMID: 37175141 PMCID: PMC10180093 DOI: 10.3390/molecules28093732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
The antioxidant drug ebselen has been widely studied in both laboratories and in clinical trials. The catalytic mechanism by which it destroys hydrogen peroxide via reduction with glutathione or other thiols is complex and has been the subject of considerable debate. During reinvestigations of several key steps, we found that the seleninamide that comprises the first oxidation product of ebselen underwent facile reversible methanolysis to an unstable seleninate ester and two dimeric products. In its reaction with benzyl alcohol, the seleninamide produced a benzyl ester that reacted readily by selenoxide elimination, with formation of benzaldehyde. Oxidation of ebselen seleninic acid did not afford a selenonium seleninate salt as previously observed with benzene seleninic acid, but instead generated a mixture of the seleninic and selenonic acids. Thiolysis of ebselen with benzyl thiol was faster than oxidation by ca. an order of magnitude and produced a stable selenenyl sulfide. When glutathione was employed, the product rapidly disproportionated to glutathione disulfide and ebselen diselenide. Oxidation of the S-benzyl selenenyl sulfide, or thiolysis of the seleninamide with benzyl thiol, afforded a transient thiolseleninate that also readily underwent selenoxide elimination. The S-benzyl derivative disproportionated readily when catalyzed by the simultaneous presence of both the thiol and triethylamine. The phenylthio analogue disproportionated when exposed to ambient or UV (360 nm) light by a proposed radical mechanism. These observations provide additional insight into several reactions and intermediates related to ebselen.
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Affiliation(s)
- Kai N Sands
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - Austin L Burman
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - Esther Ansah-Asamoah
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
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Alshammari AH, Alshammari K, Alotaibi T, Alshammari M, Alhassan S, Taha TAM. In Situ Polycondensation Synthesis of NiS-g-C 3N 4 Nanocomposites for Catalytic Hydrogen Generation from NaBH 4. Nanomaterials (Basel) 2023; 13:938. [PMID: 36903816 PMCID: PMC10005517 DOI: 10.3390/nano13050938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 02/27/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
The nanocomposites of S@g-C3N4 and NiS-g-C3N4 were synthesized for catalytic hydrogen production from the methanolysis of sodium borohydride (NaBH4). Several experimental methods were applied to characterize these nanocomposites such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and environmental scanning electron microscopy (ESEM). The calculation of NiS crystallites revealed an average size of 8.0 nm. The ESEM and TEM images of S@g-C3N4 showed a 2D sheet structure and NiS-g-C3N4 nanocomposites showed the sheet materials that were broken up during the growth process, revealing more edge sites. The surface areas were 40, 50, 62, and 90 m2/g for S@g-C3N4, 0.5 wt.% NiS, 1.0 wt.% NiS, and 1.5 wt.% NiS, respectively. The pore volume of S@g-C3N4 was 0.18 cm3, which was reduced to 0.11 cm3 in 1.5 wt.% NiS owing to the incorporation of NiS particles into the nanosheet. We found that the in situ polycondensation preparation of S@g-C3N4 and NiS-g-C3N4 nanocomposites increased the porosity of the composites. The average values of the optical energy gap for S@g-C3N4 were 2.60 eV and decreased to 2.50, 2.40, and 2.30 eV as the NiS concentration increased from 0.5 to 1.5 wt.%. All NiS-g-C3N4 nanocomposite catalysts had an emission band that was visible in the 410-540 nm range and the intensity of this peak decreased as the NiS concentration increased from 0.5 to 1.5 wt.%. The hydrogen generation rates increased with increasing content of NiS nanosheet. Moreover, the sample 1.5 wt.% NiS showed the highest production rate of 8654 mL/g·min due to the homogeneous surface organization.
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Zhao X, Wang Q, Kunthom R, Liu H. Sulfonic Acid-Grafted Hybrid Porous Polymer Based on Double-Decker Silsesquioxane as Highly Efficient Acidic Heterogeneous Catalysts for the Alcoholysis of Styrene Oxide. ACS Appl Mater Interfaces 2023; 15:6657-6665. [PMID: 36588472 DOI: 10.1021/acsami.2c17732] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
β-Alkoxyalcohols generated from epoxide ring-opening reactions are significant due to their enormous value as pharmaceutical intermediates and fine chemicals. Using a phenyl-substituted double-decker-type silsesquioxane as the precursor, a hybrid porous material (PCS-DDSQ) was synthesized through a Scholl coupling reaction with an AlCl3 catalyst. Then, novel excellent Brønsted acid-derived silsesquioxane solid catalysts (PCS-DDSQ-SO3H-x) were successfully obtained through an electrophilic aromatic substitution reaction of chlorosulfonic acid on phenyl rings of PCS-DDSQ, fully characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, powder X-ray diffraction, temperature-programmed desorption, water contact angle, Brunauer-Emmett-Teller model, thermogravimetric analysis, and solid-state 13C and 29Si nuclear magnetic resonance techniques. The catalytic behavior of the PCS-DDSQ-SO3H-x with different SO3H loadings for the methanolysis of styrene oxide was compared and evaluated. The presence of SO3H groups endows them with excellent catalytic abilities, achieving the highest values from PCS-DDSQ-SO3H-1 (the acid site of its catalyst is 1.84 mmol/g) as 99% conversion and 100% selectivity for the methanolysis of styrene oxide in 30 min, which shows superior catalytic properties of low dosage and high efficiency. Furthermore, the PCS-DDSQ-SO3H-1 catalyst can maintain high activity and selectivity after three cycles. This study provides a feasible method for the preparation of Brønsted solid acid catalysts with different acid loadings by introducing the sulfonic group into PCS-DDSQ.
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Affiliation(s)
- Xiaohan Zhao
- International Center for Interdisciplinary Research and Innovation of Silsesquioxane Science, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Qingzheng Wang
- International Center for Interdisciplinary Research and Innovation of Silsesquioxane Science, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, P. R. China
- Department of Chemistry and Chemical Biology, Graduate School of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Rungthip Kunthom
- International Center for Interdisciplinary Research and Innovation of Silsesquioxane Science, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Hongzhi Liu
- International Center for Interdisciplinary Research and Innovation of Silsesquioxane Science, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, P. R. China
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Cruz-Rubio JM, Riva A, Cybulska J, Zdunek A, Berry D, Loeppert R, Viernstein H, Praznik W, Maghuly F. Neutral and Pectic Heteropolysaccharides Isolated from Opuntia joconostle Mucilage: Composition, Molecular Dimensions and Prebiotic Potential. Int J Mol Sci 2023; 24. [PMID: 36834619 DOI: 10.3390/ijms24043208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 02/07/2023] Open
Abstract
Opuntia joconostle is a semi-wild cactus cultivated for its fruit. However, the cladodes are often discarded, wasting the potentially useful mucilage in them. The mucilage is composed primarily of heteropolysaccharides, characterized by their molar mass distribution, monosaccharide composition, structural features (by vibrational spectroscopy, FT IR, and atomic force microscopy, AFM), and fermentability by known saccharolytic commensal members of the gut microbiota. After fractionation with ion exchange chromatography, four polysaccharides were found: one neutral (composed mainly of galactose, arabinose, and xylose) and three acidic, with a galacturonic acid content from 10 to 35%mol. Their average molar masses ranged from 1.8 × 105 to 2.8 × 105 g·mol-1. Distinct structural features such as galactan, arabinan, xylan, and galacturonan motifs were present in the FT IR spectra. The intra- and intermolecular interactions of the polysaccharides, and their effect on the aggregation behavior, were shown by AFM. The composition and structural features of these polysaccharides were reflected in their prebiotic potential. Lactobacilli and Bifidobacteria were not able to utilize them, whereas members of Bacteroidetes showed utilization capacity. The obtained data suggest a high economic potential for this Opuntia species, with potential uses such as animal feed in arid areas, precise prebiotic, and symbiotic formulations, or as the carbon skeleton source in a green refinery. Our methodology can be used to evaluate the saccharides as the phenotype of interest, helping to guide the breeding strategy.
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Feng Y, Zhang X, Shao Y, Chen X, Wang H, Li J, Wu M, Dong H, Liu Q, Li H. Modulating the Acidic Properties of Mesoporous Mo x-Ni 0.8Cu 0.2O Nanowires for Enhanced Catalytic Performance toward the Methanolysis of Ammonia Borane for Hydrogen Production. ACS Appl Mater Interfaces 2022; 14:27979-27993. [PMID: 35674395 DOI: 10.1021/acsami.2c06234] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Rational construction of inexpensive, highly efficient, and stable catalysts for ammonia borane (AB) methanolysis is in high demand but still remains a great challenge. In this work, we have successfully fabricated uniform Mox-Ni0.8Cu0.2O nanowires using a simple hydrothermal method followed by a post-calcination treatment and flexibly modulated the acidity of their surface by changing the amount of Mo introduced into Ni0.8Cu0.2O. The Mo0.1-Ni0.8Cu0.2O catalyst displayed strong catalytic activity toward AB methanolysis with an ultrahigh turnover frequency of 46.9 molH2 molcat.-1 min-1, which is even higher than some noble metal catalysts. In this work, an equation regarding the relationship between the quantity of moderated acid sites of catalysts and its corresponding activity toward AB methanolysis was first determined. A plausible mechanism for AB methanolysis catalyzed by Mox-Ni0.8Cu0.2O was proposed, and the benefits of the introduction of MoO3 to Ni0.8Cu0.2O for enhancing the catalytic performance were also discussed. These findings can form a basis for the rational construction of inexpensive catalysts with robust performance toward AB methanolysis for hydrogen production.
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Affiliation(s)
- Yufa Feng
- School of Chemistry and Materials Engineering, Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China
| | - Xuefeng Zhang
- School of Chemistry and Materials Engineering, Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China
| | - Youxiang Shao
- School of Chemistry and Materials Engineering, Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China
| | - Xiaodong Chen
- School of Chemistry and Materials Engineering, Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China
| | - Huize Wang
- School of Chemistry and Materials Engineering, Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China
| | - Junhao Li
- Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Ming Wu
- Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Huafeng Dong
- School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Quanbing Liu
- Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Hao Li
- School of Chemistry and Materials Engineering, Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices, Huizhou University, Huizhou 516007, China
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Lamberti FM, Román-Ramírez LA, Dove AP, Wood J. Methanolysis of Poly(lactic Acid) Using Catalyst Mixtures and the Kinetics of Methyl Lactate Production. Polymers (Basel) 2022; 14:polym14091763. [PMID: 35566932 PMCID: PMC9105383 DOI: 10.3390/polym14091763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022] Open
Abstract
Polylactic acid (PLA) is a leading bioplastic of which the market share is predicted to increase in the future; its growing production capacity means its end-of-life treatment is becoming increasingly important. One beneficial disposal route for PLA is its chemical recycling via alcoholysis. The alcoholysis of PLA leads to the generation of value-added products alkyl lactates; this route also has potential for a circular economy. In this work, PLA was chemically recycled via methanolysis to generate methyl lactate (MeLa). Four commercially available catalysts were investigated: zinc acetate dihydrate (Zn(OAc)2), magnesium acetate tetrahydrate (Mg(OAc)2), 4-(dimethylamino)pyridine (DMAP), and triazabicyclodecene (TBD). Dual catalyst experiments displayed an increase in reactivity when Zn(OAc)2 was paired with TBD or DMAP, or when Mg(OAc)2 was paired with TBD. Zn(OAc)2 coupled with TBD displayed the greatest reactivity. Out of the single catalyst reactions, Zn(OAc)2 exhibited the highest activity: a higher mol% was found to increase reaction rate but plateaued at 4 mol%, and a higher equivalent of methanol was found to increase the reaction rate, but plateaued at 17 equivalents. PLA methanolysis was modelled as a two-step reversible reaction; the activation energies were estimated at: Ea1 = 25.23 kJ∙mol−1, Ea2 = 34.16 kJ∙mol−1 and Ea-2 = 47.93 kJ∙mol−1.
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Affiliation(s)
- Fabio M. Lamberti
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
| | - Luis A. Román-Ramírez
- Division of Chemical and Energy Engineering, London South Bank University, 103 Borough Road, London SE1 0AA, UK;
| | - Andrew P. Dove
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
| | - Joseph Wood
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- Correspondence:
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Su S, Kopitzky R, Berrenrath C. Experimental Determination of Molecular Weight-Dependent Miscibility of PBAT/PLA Blends. Polymers (Basel) 2021; 13:3686. [PMID: 34771243 DOI: 10.3390/polym13213686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/11/2021] [Accepted: 10/20/2021] [Indexed: 01/31/2023] Open
Abstract
Blends of poly(butylene adipate-co-terephthalate) (PBAT) and polylactide (PLA) have attracted the attention of academia and industry as a sustainable material. Unfortunately, this combination results in problems related to poor miscibility on the molecular level. This study mainly aims to determine the influence of molecular weights on the miscibility of PBAT/PLA blends. First, polymers with various molecular weights were obtained by the hydrolysis of PBAT and methanolysis of PLA. Second, the two components were solution-blended with different molecular weights and weight ratios. Third, each blend was heated to the molten state and subsequently stored at room temperature. Finally, the samples were tested using DSC and SEM. The thermal analysis indicated that the difference in glass transition temperature between both components decreased from about 91 °C to 57 °C and 0 °C, as the number-average molecular weights (Mn) decreased from 52/127 to 9.4/9 and 6.3/6.6 kg/mol. Moreover, the morphology changed from phase-separated with dispersed large particles gradually to uniform and homogeneous. This experimental work validated the trends predicted in the previous study, namely that PBAT/PLA blends changed the state from immiscible to partially miscible to fully miscible with decreasing Mn values. Moreover, we discussed the influencing factors such as weight ratio, temperature, and molecular structure on the miscibility. Based on the results, this work contributes to developing partially miscible and compatible blends without additives.
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Abstract
The polyethylene terephthalate (PET) application has many challenges and potential due to its sustainability. The conventional PET degradation was developed for several technologies to get higher yield products of ethylene glycol, bis(2-hydroxyethyl terephthalate) and terephthalic acid. The chemical recycling of PET is reviewed, such as pyrolysis, hydrolysis, methanolysis, glycolysis, ionic-liquid, phase-transfer catalysis and combination of glycolysis-hydrolysis, glycolysis-methanolysis and methanolysis-hydrolysis. Furthermore, the reaction kinetics and reaction conditions were investigated both theoretically and experimentally. The recycling of PET is to solve environmental problems and find another source of raw material for petrochemical products and energy.
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Affiliation(s)
- Damayanti
- Department of Chemical Engineering, Institut Teknologi Sumatera, Lampung Selatan, Lampung 35365, Indonesia;
- Department of Chemical Engineering and Materials Science, Yuan Ze University, 135 Yuan-Tung Road, Chung-Li, Taoyuan 32003, Taiwan
| | - Ho-Shing Wu
- Department of Chemical Engineering and Materials Science, Yuan Ze University, 135 Yuan-Tung Road, Chung-Li, Taoyuan 32003, Taiwan
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BaĞuÇ İB, Yurderİ M, Saydan KanberoĞlu G, Bulut A. Hydrotalcite framework stabilized ruthenium nanoparticles (Ru/HTaL): efficient heterogeneous catalyst for the methanolysis of ammonia-borane. Turk J Chem 2021; 44:364-377. [PMID: 33488163 PMCID: PMC7671226 DOI: 10.3906/kim-1910-44] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/14/2020] [Indexed: 11/11/2022] Open
Abstract
Ruthenium nanoparticles stabilized by a hydrotalcite framework (Ru/HTaL) were prepared by following a 2-step procedure comprising a wet-impregnation of ruthenium(III) chloride precatalyst on the surface of HTaL followed by an ammonia-borane (NH3BH3) reduction of precatalyst on the HTaL surface all at room temperature. The characterization of Ru/HTaL was done by using various spectroscopic and visualization methods including ICP-OES, P-XRD, FTIR, 11B NMR, XPS, BFTEM, and HRTEM. The sum of the results gained from these analyses has revealed the formation of well-dispersed and highly crystalline ruthenium nanoparticles with a mean diameter of 1.27 ±0.8 nm on HTaL surface. The catalytic performance of Ru/HTaL in terms of activity, selectivity, and stability was investigated in the methanolysis of ammonia-borane (NH3BH3 , AB), which has been considered as one of the most promising chemical hydrogen storage materials. It was found that Ru/HTaL can catalyse methanolysis of AB effectively with an initial turnover frequency (TOF) value of 392.77 min-1 at conversion (>95%) even at room temperature. Moreover, the catalytic stability tests of Ru/HTaL in AB methanolysis showed that Ru/HTaL acts as a highly stable and reusable heterogeneous catalyst in this reaction by preserving more than 95% of its initial activity even at the 5th recycle.
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Affiliation(s)
- İsmail Burak BaĞuÇ
- Department of Chemistry, Faculty of Science, Van Yüzüncü Yıl University, Van Turkey
| | - Mehmet Yurderİ
- Department of Chemistry, Faculty of Science, Van Yüzüncü Yıl University, Van Turkey
| | | | - Ahmet Bulut
- Department of Chemistry, Faculty of Science, Van Yüzüncü Yıl University, Van Turkey
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Zhai Q, Hse CY, Long F, Shupe TF, Wang F, Jiang J, Xu J. Methanolysis Fractionation and Catalytic Conversion of Poplar Wood toward Methyl Levulinate, Phenolics, and Glucose. J Agric Food Chem 2019; 67:9840-9850. [PMID: 31424924 DOI: 10.1021/acs.jafc.9b03806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In the present study, methanolysis of poplar biomass was conducted for the selective transformation of hemicellulose and lignin, which leads to methyl glycosides (mainly C5 glycosides) and lignin fragments in the liquefied products that can be separated according to their difference in hydrophilicity. The distribution of methyl glycosides and delignification was dependent on the presence of acid catalysts and reaction temperatures. The obtained lignin fraction was separated into solid lignin fragments and liquid lignin oil according to their molecular weight distribution. Subsequently, directional conversion of methyl C5 glycosides into methyl levulinate was performed with dimethoxymethane/methanol as the cosolvent. A yield of 12-30% of methyl levulinate yield (based on the methyl glycoside) was achieved under these conditions. The remaining cellulose-rich substrate showed enhanced susceptibility to enzymatic hydrolysis, resulting in a yield of glucose of above 70%. Overall, the described strategy shows practical implications for the effective valorization of biomass.
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Affiliation(s)
- Qiaolong Zhai
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry , Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. on Forest Chemical Engineering , SFA, Nanjing 210042 , People's Republic of China
| | - Chung-Yun Hse
- United States Department of Agriculture (USDA) Forest Service , Southern Research Station , Pineville , Louisiana 71360 , United States
| | - Feng Long
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry , Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. on Forest Chemical Engineering , SFA, Nanjing 210042 , People's Republic of China
| | - Todd F Shupe
- Wood Science Consulting, LLC , Baton Rouge , Louisiana 70816 , United States
| | - Fei Wang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry , Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. on Forest Chemical Engineering , SFA, Nanjing 210042 , People's Republic of China
| | - Jianchun Jiang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry , Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. on Forest Chemical Engineering , SFA, Nanjing 210042 , People's Republic of China
| | - Junming Xu
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry , Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. on Forest Chemical Engineering , SFA, Nanjing 210042 , People's Republic of China
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources , Nanjing Forestry University , Nanjing , 210037 , People's Republic of China
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Podniesińska L, Frański R, Frańska M. Comparison of the electrospray ionization (ESI) responses of penicillins with ESI responses of their methanolysis products. Eur J Mass Spectrom (Chichester) 2019; 25:357-361. [PMID: 30582710 DOI: 10.1177/1469066718820434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The electrospray ionization (ESI) responses, defined as the area of chromatographic peak of ion [M+H]+ obtained upon HPLC/ESI-MS analysis, of three β-lactam antibiotics, namely penicillin G, ampicillin and carbenicillin have been compared with the ESI responses of their methanolysis products. It has been found that methanolyzed penicillin G has much higher ESI response than the penicillin G. Methanolyzed ampicillin also has higher ESI response than ampicillin; however, the effect is less pronounced than for penicillin. Methanolyzed carbenicillin does not have pronouncedly higher ESI response than carbenicillin.
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Affiliation(s)
| | - Rafał Frański
- 1 Faculty of Chemistry, Adam Mickiewicz University, Poznań, Poland
| | - Magdalena Frańska
- 2 Institute of Chemistry and Technical Electrochemistry, Poznań University of Technology, Poznań, Poland
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Luo W, Cheng W, Hu M, Wang Q, Cheng X, Zhang Y, Wang Y, Gao D, Bi J, Fan G. Ultrahigh Catalytic Activity of l-Proline-Functionalized Rh Nanoparticles for Methanolysis of Ammonia Borane. ChemSusChem 2019; 12:535-541. [PMID: 30383321 DOI: 10.1002/cssc.201802157] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/21/2018] [Indexed: 06/08/2023]
Abstract
The synthesis of ultrafine and well-distributed rhodium nanoparticles (NPs) with high efficiency toward methanolysis of ammonia borane (AB) is crucially important but challenging. A facile approach has been developed for synthesizing ultrafine and uniform Rh NPs deposited on carbon by using the small soluble organic molecule (SOM) of l-proline (PRO) as capping agent (Rh-PRO/C). The enrichment of N,O-coordination sites for the metal precursor by using PRO was found to be the key to the synthesis Rh-PRO/C. The as-prepared Rh-PRO/C showed high catalytic activity for ammonia borane methanolysis with the highest total turnover frequency (TOF) of 1035 mol H 2 (molRh min)-1 under basic conditions, which was three times higher than that of the state-of-the-art Rh-based catalysts. The excellent catalytic performance of Rh-PRO/C was ascribed to the well-dispersed Rh NPs and the PRO-functionalized metal surface, which can provide more active sites for the reaction. The merit of size-controlled synthesis combined with metal NP surface modification by SOMs is likely to be beneficial in various catalytic fields.
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Affiliation(s)
- Wenxiu Luo
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Wei Cheng
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Min Hu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Qi Wang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Xia Cheng
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Yun Zhang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Yi Wang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Daojiang Gao
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Jian Bi
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Guangyin Fan
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
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Silva FBD, Morais Júnior WGD, Silva CVD, Vieira AT, Batista ACF, Faria AMD, Assunção RMN. Preparation and Characterization of Cellulose Triacetate as Support for Lecitase Ultra Immobilization. Molecules 2017; 22:molecules22111930. [PMID: 29144385 PMCID: PMC6150194 DOI: 10.3390/molecules22111930] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/31/2017] [Accepted: 11/06/2017] [Indexed: 11/16/2022] Open
Abstract
The use of polymers as supports for enzyme immobilization is a strategy that enables to remove the enzymes from a chemical reaction and improve their efficiency in catalytic processes. In this work, cellulose triacetate (CTA) was used for physical adsorption of phospholipase Lecitase ultra (LU). CTA is more hydrophobic than cellulose, shows good performance in the lipases immobilization being a good candidate for immobilization of phospholipases. We investigated the immobilization of LU in CTA, the stability of the immobilized enzyme (CTA-LU) and the performance of CTA-LU using soybean oil as a substrate. LU was efficiently immobilized in CTA reaching 97.1% in 60 min of contact with an enzymatic activity of 975.8 U·g-1. The CTA-LU system presents good thermal stability, being superior of the free enzyme and increase of the catalytic activity in the whole range of pH values. The difference observed for immobilized enzyme compared to free one occurs because of the interaction between the enzyme and the polymer, which stabilizes the enzyme. The CTA-LU system was used in the transesterification of soybean oil with methanol, with the production of fatty acid methyl esters. The results showed that CTA-LU is a promising system for enzymatic reactions.
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Affiliation(s)
- Francielle Batista da Silva
- Laboratory of Polymers Recycling, Chemistry Institute, Federal University of Uberlândia, Uberlândia 38408-144, MG, Brazil.
| | | | - Cleuzilene Vieira da Silva
- Laboratory of Polymers Recycling, Chemistry Institute, Federal University of Uberlândia, Uberlândia 38408-144, MG, Brazil.
| | - Andressa Tironi Vieira
- Faculty of Integrated Sciences-FACIP, Federal University of Uberlândia, Ituiutaba 38304-402, MG, Brazil.
| | | | - Anízio Márcio de Faria
- Faculty of Integrated Sciences-FACIP, Federal University of Uberlândia, Ituiutaba 38304-402, MG, Brazil.
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Newsome AG, Li Y, van Breemen RB. Improved Quantification of Free and Ester-Bound Gallic Acid in Foods and Beverages by UHPLC-MS/MS. J Agric Food Chem 2016; 64:1326-1334. [PMID: 26804199 DOI: 10.1021/acs.jafc.5b04966] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hydrolyzable tannins are measured routinely during the characterization of food and beverage samples. Most methods for the determination of hydrolyzable tannins use hydrolysis or methanolysis to convert complex tannins to small molecules (gallic acid, methyl gallate, and ellagic acid) for quantification by HPLC-UV. Often unrecognized, analytical limitations and variability inherent in these approaches for the measurement of hydrolyzable tannins include the variable mass fraction (0-0.90) that is released as analyte, contributions of sources other than tannins to hydrolyzable gallate (can exceed >10 wt %/wt), the measurement of both free and total analyte, and lack of controls to account for degradation. An accurate, specific, sensitive, and higher-throughput approach for the determination of hydrolyzable gallate based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) that overcomes these limitations was developed.
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Affiliation(s)
- Andrew G Newsome
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy , 833 South Wood Street, Chicago, Illinois 60642, United States
| | - Yongchao Li
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy , 833 South Wood Street, Chicago, Illinois 60642, United States
| | - Richard B van Breemen
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy , 833 South Wood Street, Chicago, Illinois 60642, United States
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Abstract
A convenient method using commercial aqueous concentrated HCl (conc. HCl; 35%, w/w) as an acid catalyst was developed for preparation of fatty acid methyl esters (FAMEs) from sterol esters, triacylglycerols, phospholipids, and FFAs for gas-liquid chromatography (GC). An 8% (w/v) solution of HCl in methanol/water (85:15, v/v) was prepared by diluting 9.7 ml of conc. HCl with 41.5 ml of methanol. Toluene (0.2 ml), methanol (1.5 ml), and the 8% HCl solution (0.3 ml) were added sequentially to the lipid sample. The final HCl concentration was 1.2% (w/v). This solution (2 ml) was incubated at 45 degrees C overnight or heated at 100 degrees C for 1-1.5 h. The amount of FFA formed in the presence of water derived from conc. HCl was estimated to be <1.4%. The yields of FAMEs were >96% for the above lipid classes and were the same as or better than those obtained by saponification/methylation or by acid-catalyzed methanolysis/methylation using commercial anhydrous HCl/methanol. The method developed here could be successfully applied to fatty acid analysis of various lipid samples, including fish oils, vegetable oils, and blood lipids by GC.
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Affiliation(s)
- Ken'ichi Ichihara
- Biological Chemistry Graduate School of Agricultural Science, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan.
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