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1.
Small ; 14(3)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29227019

RESUMO

Recently, sodium-ion batteries (SIBs) are extensively explored and are regarded as one of the most promising alternatives to lithium-ion batteries for electrochemical energy conversion and storage, owing to the abundant raw material resources, low cost, and similar electrochemical behavior of elemental sodium compared to lithium. Metal-organic frameworks (MOFs) have attracted enormous attention due to their high surface areas, tunable structures, and diverse applications in drug delivery, gas storage, and catalysis. Recently, there has been an escalating interest in exploiting MOF-derived materials as anodes for sodium energy storage due to their fast mass transport resulting from their highly porous structures and relatively simple preparation methods originating from in situ thermal treatment processes. In this Review, the recent progress of the sodium-ion storage performances of MOF-derived materials, including MOF-derived porous carbons, metal oxides, metal oxide/carbon nanocomposites, and other materials (e.g., metal phosphides, metal sulfides, and metal selenides), as SIB anodes is systematically and completely presented and discussed. Moreover, the current challenges and perspectives of MOF-derived materials in electrochemical energy storage are discussed.

2.
Anal Chem ; 89(5): 2800-2806, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28192980

RESUMO

Although higher resolving powers are often achieved using ambient pressure drift tube ion mobility mass spectrometry (DT-IMMS) systems, lower duty cycles are often required which directly impacts sensitivity. Moreover, the mechanism of ion gating using Bradbury-Nielsen or Tyndall-Gate configurations routinely results in ion gate depletion effects which discriminate against low mobility ions. This paper reports a new method of ambient pressure ion mobility operation in which inverse ion mobility spectrometry is coupled to a time-of-flight mass spectrometer to improve sensitivity and minimize the effects of ion gate depletion. In this mode of operation, the duty cycle is improved to approximate 99% from a typical value of less than 1%, improving the signal intensity by over 2 orders of magnitude. Another advantage of inverse ion mobility mass spectrometry is a reduction of the impact of ion gate depletion on low mobility molecules that translates into higher sensitivity for this class of analytes. To demonstrate these benefits afforded by this instrumental mode of operation differences in sensitivity, resolving power, and ion discrimination are compared between the inverse and normal modes of operation using tetraalkylammonium standards. These results show that the ion throughput is significantly increased for analytes with a broad range of mobilities with little impact on resolving power. While the mobility-based discrimination is minimized using the inverse mode of operation, the noise level in the inverse mode is highly dependent upon the stability of ionization source.

3.
Bioconjug Chem ; 28(10): 2514-2517, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-28876900

RESUMO

The low abundance of sialo-glycoprotein hampered the separation, enrichment, and analysis of sialo-glycoproteins, which are critical for studying their functions. Here, we designed cleavable amino-oxy functionalized magnetic materials and employed to fast and selective isolate sialo-glycoproteins. This includes the ligation of disulfide-linked amino-oxy-functionalized magnetic nanoparticles with periodate-treated glycoproteins or cells, followed by magnetic separation. A reductive reagent could release the sialo-glycoproteins with small molecular fragments on the terminal of glycan chains, and the sialo-glycoproteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. On-bead digestion of the peptides were analyzed by tandem mass spectrometry. The results indicated that this method could selectively separate the majority of cell-surface sialo-glycoproteins.


Assuntos
Dissulfetos/química , Glicoproteínas/química , Glicoproteínas/isolamento & purificação , Nanopartículas de Magnetita/química , Humanos , Células Jurkat
4.
Environ Sci Technol ; 49(17): 10570-80, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26237660

RESUMO

The discharge of metals and dyes poses a serious threat to public health and the environment. What is worse, these two hazardous pollutants are often found to coexist in industrial wastewaters, making the treatment more challenging. Herein, we report an EDTA-cross-linked ß-cyclodextrin (EDTA-ß-CD) bifunctional adsorbent, which was fabricated by an easy and green approach through the polycondensation reaction of ß-cyclodextrin with EDTA as a cross-linker, for simultaneous adsorption of metals and dyes. In this setting, cyclodextrin cavities are expected to capture dye molecules through the formation of inclusion complexes and EDTA units as the adsorption sites for metals. The adsorbent was characterized by FT-IR, elemental analysis, SEM, EDX, ζ-potential, and TGA. In a monocomponent system, the adsorption behaviors showed a monolayer adsorption capacity of 1.241 and 1.106 mmol g(-1) for Cu(II) and Cd(II), respectively, and a heterogeneous adsorption capacity of 0.262, 0.169, and 0.280 mmol g(-1) for Methylene Blue, Safranin O, and Crystal Violet, respectively. Interestingly, the Cu(II)-dye binary experiments showed adsorption enhancement of Cu(II), but no significant effect on dyes. The simultaneous adsorption mechanism was further confirmed by FT-IR, thermodynamic study, and elemental mapping. Overall, its facile and green fabrication, efficient sorption performance, and excellent reusability indicate that EDTA-ß-CD has potential for practical applications in integrative and efficient treatment of coexistenting toxic pollutants.


Assuntos
Corantes/isolamento & purificação , Reagentes de Ligações Cruzadas/química , Ácido Edético/química , Química Verde , Metais/isolamento & purificação , beta-Ciclodextrinas/química , Adsorção , Cátions , Violeta Genciana/química , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno/química , Temperatura , Têxteis , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/química
5.
Bioresour Technol ; 403: 130858, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38777229

RESUMO

Pentanediols are substances with significant market potential as the key monomers for advanced polymeric materials. In this study, we successfully achieved directly hydrogenolysis of biomass-based furfural to 1,5-pentanediol with a remarkable yield of 53.4 % using Cu-modified cobalt supported on cerium dioxide catalysts. Through comprehensive characterization techniques, including H2-TPR, NH3-TPD, XPS, EPR and Raman analysis, the study revealed that the introduction of Cu altered the dispersion of Co species, attenuated the interaction between Co species and cerium dioxide, enhanced its reduction extent, and fostered the formation of plentiful cobalt oxide species and oxygen vacancies on the catalyst's surface. The cooperative influence of Cu and Co heightened the selectivity of the hydrogenolysis reaction. This work provides a novel strategy for the development of greener and more efficient catalytic processes based on non-precious metals that for the selective conversion of biomass-derived furfural to high-value pentanediols.


Assuntos
Cobalto , Cobre , Furaldeído , Cobalto/química , Catálise , Cobre/química , Furaldeído/química , Cério/química , Glicóis/química , Biomassa
6.
ChemSusChem ; : e202401017, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38924639

RESUMO

2, 5-Dimethylfuran (DMF), which is a promising new-generation liquid biofuel, has attracted widespread attention owing to the sustainability of biomass-derived energy sources. In this study, a highly dispersed zirconia-supported nickel catalyst (CA-Ni/ZrO2) was prepared via citric acid-assisted wetness impregnation for the selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) to produce DMF. The characterization results confirmed the presence of Zr3+ species in the mesoporous CA-Ni/ZrO2 catalyst and the formation of oxygen vacancies during its preparation, which led to the formation of a large number of catalytically active sites for the adsorption and activation of the C=O/C-O groups. Under appropriate reaction parameters, an excellent DMF selectivity of 99.1 % and an HMF conversion of 98.4 % were achieved. A suitable kinetic model revealed that DMF was preferentially formed via the 2,5-dihydroxymethylfuran intermediate route, although a 5-methylfurfural route was also observed. Additionally, the interaction between Ni and ZrO2 significantly affected the stability of the catalyst. This study will provide guidelines for optimizing the catalytic conversion of furan derivatives over heterogeneous catalysts.

7.
Anal Chem ; 85(10): 5263-70, 2013 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-23600895

RESUMO

An alternative method for labeling fully replicative enveloped viruses was developed, in which both the biosynthesis and metabolic incorporation of phospholipids in host cells were simultaneously utilized to introduce an azide group to the envelope of the vaccinia virus by taking advantage of the host-derived lipid membrane formation mechanism. Such an azide group could be subsequently used to fluorescently label the envelope of the virus via a bioorthogonal reaction. Furthermore, simultaneous dual-labeling of the virus through the virus replication was realized skillfully by coupling this envelope labeling strategy with "replication-intercalation labeling" of viral nucleic acid. For the first time, it is by natural propagation of the virus in its host cells in the presence of fluorophores that simultaneous dual-labeling of living viruses can be mildly realized with high efficiency in facile and mild conditions.


Assuntos
Vírus da Influenza A Subtipo H9N2/metabolismo , Fosfatidilcolinas/biossíntese , Fosfatidilcolinas/metabolismo , Coloração e Rotulagem/métodos , Vaccinia virus/metabolismo , Alcinos/química , Animais , Azidas/química , Materiais Biocompatíveis/química , Chlorocebus aethiops , Cães , Vírus da Influenza A Subtipo H9N2/fisiologia , Células Madin Darby de Rim Canino , Viabilidade Microbiana , Fosfatidilcolinas/química , Vaccinia virus/fisiologia , Células Vero , Replicação Viral
8.
Nanomaterials (Basel) ; 13(9)2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37177099

RESUMO

It is presented that the activated carbon was carboxylated with hydrogen peroxide and then acylated with 2-methylimidazole to prepare the porous carbon support with a surface imidazolated modification. Through the adsorption of phosphotungstic acid on the fundamental site of an imidazolyl group and then adjusting the acid strength with the ammonia molecule, a catalytic carbon material immobilized with ammonium phosphotungstate (AC-COIMO-NH4PW) was obtained, which was used to catalyze a one-pot reaction of convenient α-pinene and hydrogen peroxide to sobrerol. The bifunctional active site originated from the dual property of ammonium phosphotungstate, as the oxidant and acid presenting a cooperatively catalytic performance, which effectively catalyzes the tandem epoxidation-isomerization-hydration of α-pinene to sobrerol, in which the solvent effect of catalysis simultaneously exists. The sobrerol selectivity was significantly improved after the acid strength weakening by ammonia. Monomolecular chemical bonding and anchoring of ammonium phosphotungstate at the basic site prevented the loss of the active catalytic species, and the recovered catalyst showed excellent catalytic stability in reuse. Using acetonitrile as the solvent at 40 °C for 4 h, the conversion of α-pinene could reach 90.6%, and the selectivity of sobrerol was 40.5%. The results of five cycles show that the catalyst presents excellent stability due to the tight immobilization of ammonium phosphotungstate bonding on the imidazolized activated carbon, based on which a catalytic-cycle mechanism is proposed for the tandem reaction.

9.
Front Chem ; 10: 925622, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35844654

RESUMO

Keggin-type phosphotungstic acid (HPW) supported on imidazolyl-activated carbon (AC-COIMI-HPW) catalysts was prepared, which was used to catalyze the oxidation of benzyl alcohol with aqueous H2O2. In the presence of AC-COIMI-HPW, the benzyl alcohol conversion of 90.2% with 91.8% selectivity of benzaldehyde was obtained at 90°C for 6 h in an acetonitrile aqueous solution. The catalyst exhibited an outstanding performance for the oxidation of various benzyl alcohols and aliphatic alcohols. In addition, the catalyst could be easily recovered and reused five times without significant deactivation. The characterization results showed that HPW was chemically bonded on the surface of the carbon material through an ionic bond. It is proposed that the combination of the imidazole cation with the HPW anion could not only tune the redox catalytic properties of the PW anion but also enhance the compatibility of the catalyst in the reaction medium, thereby improving the catalytic performance.

10.
Nanomaterials (Basel) ; 12(9)2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35564172

RESUMO

Through the amination of oxidized activated carbon with ethylenediamine and then the adsorption of sulfuric acid, a strong carbon-based solid acid catalyst with hydrogen sulfate (denoted as AC-N-SO4H) was prepared, of which the surface acid density was 0.85 mmol/g. The acetalization of benzaldehyde with ethylene glycol catalyzed by AC-N-SO4H was investigated. The optimized catalyst dosage accounted for 5 wt.% of the benzaldehyde mass, and the molar ratio of glycol to benzaldehyde was 1.75. After reacting such mixture at 80 °C for 5 h, the benzaldehyde was almost quantitatively converted into acetal; the conversion yield was up to 99.4%, and no byproduct was detected. It is surprising that the catalyst could be easily recovered and reused ten times without significant deactivation, with the conversion yield remaining above 99%. The catalyst also exhibited good substrate suitability for the acetalization of aliphatic aldehydes and the ketalization of ketones with different 1,2-diols.

11.
Front Chem ; 10: 959572, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36017159

RESUMO

γ-Valerolactone (GVL) is one of the most valuable compounds derived from furfural (FAL), which has been industrially produced from agricultural byproducts like corn cobs. It is extremely challenging to synthesize GVL from FAL efficiently via a one-pot cascade reaction due to the need for multiple active sites in a single pot. By focusing on the aspects of one-pot synthesis of GVL from FAL, the authors aim to shed light on the rational design and utilization of environmentally friendly bifunctional catalysts with high efficiency in this reaction. Perspectives regarding future research opportunities in bi- or multi-functional catalysts for one-pot GVL synthesis are also discussed.

12.
Front Chem ; 10: 853112, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35372283

RESUMO

2, 5-Furandicarboxylic acid (FDCA) is an important bio-monomer that can potentially replace terephthalic acid to synthesize degradable polyesters. Efficient selective oxidation of biomass-based 5-hydroxymethylfurfural (HMF) to FDCA has been a significant but challenging work in the past decades. In this study, a novel molybdenum-vanadium oxide (Mo-V-O) catalyst was prepared by a simple method and showed excellent catalytic activity for converting HMF to FDCA. A high FDCA selectivity of 94.5 and 98.2% conversion of HMF were achieved under the optimal conditions with tert-butyl hydroperoxide as the oxidant. FT-IR, SEM, XRD and TG were applied to investigate the properties of Mo-V-O catalyst. After fitting experimental data with the first-order kinetics equation, the evaluated apparent activation energies of HMF oxidation were obtained. The experimental design and study were carried out by response surface methodology (RSM) to test the effects of reaction conditions on the catalytic process.

13.
Front Chem ; 10: 944398, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35800030

RESUMO

With activated carbon as raw material, AC-Ph-SO3H was prepared after oxidation with nitric acid, modification with halogenated benzene and sulfonation with concentrated sulfuric acid. After modified by 10% bromobenzene with toluene as a solvent for 5 h, followed sulfonation with concentrated sulfuric acid at 150°C, the -SO3H content of prepared AC-Ph-SO3H was 0.64 mmol/g. Acid content test, infrared spectroscopy and Raman spectroscopy detection proved that the surface of AC-Ph-SO3H was successfully grafted with -SO3H group. When used as a catalyst for the methylation of palmitate acid, the catalytic performance of AC-Ph-SO3H was explored. When the reaction time was 6 h, the amount of catalyst acid accounted for 2.5 wt% of palmitic acid, and the molar ratio of methanol/palmitic acid was 40, the esterification rate of palmitic acid was 95.2% and the yield of methyl palmitate was 94.2%, which was much better than those of its precursors AC, AC-O, and AC-Ph (both about 4.5%). AC-Ph-SO3H exhibited certain stability in the esterification reaction system and the conversion rate of palmitic acid was still above 80% after three reuses.

14.
Front Chem ; 10: 894965, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35586268

RESUMO

The titania nanotubes-bonded sulfamic acid (TNTs-NHSO3H) catalyst was designed and successfully fabricated by the post-synthesis modification method. The as-prepared catalyst was characterized by a variety of characterization techniques, including Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and thermogravimetry-differential thermal gravimetry (TG-DTG). The crystal structure of the TNTs still maintained during the modification process. Although the BET surface area was decreased, the amount of Brønsted acid sites can be efficiently fabricated on the TNTs. The catalytic activity of TNTs-NHSO3H was examined for the synthesis of n-butyl levulinate (BL) from levulinic acid (LA) and furfuryl alcohol (FA). A relatively high selectivity (99.6%) at 99.3% LA conversion was achieved for esterification of levulinic acid owing to the strong Brønsted acidity sites. And also, the TNTs-NHSO3H catalyst exhibited a higher reactivity for alcoholysis of FA and the yield of BL reached 90.4% with 100% FA conversion was obtained under the mild conditions.

15.
Phys Chem Chem Phys ; 13(24): 11644-56, 2011 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-21603695

RESUMO

Structural and chemical properties of the small water clusters W(4), W(5) and W(6) are investigated with the theory of atoms and molecules (QTAIM). For the W(4), W(5) and W(6) clusters, nine, fourteen and twenty-seven conformers, respectively, have been analyzed. For the W(4), W(5) and W(6) clusters one, two and three of these structures, respectively, have not been reported before. We then proceed to extend the W(4), W(5) and W(6) water cluster topology space using QTAIM; the Poincaré-Hopf topological sum rules are applied to create rules to identify the spanning set of conformer topologies, this includes finding three, ten and eight new distinct topologies that satisfy the Poincaré-Hopf relation for W(4), W(5) and W(6) respectively. The topological stability of degenerate solutions to the Poincaré-Hopf relation is compared by evaluating the proximity to rupturing of critical points of the gradient vector field of the charge density. We introduce a QTAIM topology space to replace the inconsistent use of Euclidean geometry to determine whether a cluster is 1-, 2- or 3-D. We show from the topology of the charge density that the conformers of the W(4), W(5) clusters are more energetically stable in less compact, planar forms, conversely the conformers of W(6) are more energetically stable with compact 3-D topologies. Quantifying the degree of covalent character in the hydrogen bonding for the W(4), W(5) and W(6) clusters independently verifies this finding. Differences in simple rules for the number of hydrogen bonds obeying the Bernal-Fowler ice rules between W(4), W(5) and W(6) reflect the transition from 2-D to 3-D structures being more energetically stable. In addition, we identify a new class of O-O bonding interactions that are up to 48% longer than the inter-nuclear separation and appear to be failed hydrogen bonds.

16.
J Phys Chem A ; 115(45): 12503-11, 2011 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21557588

RESUMO

Structural and chemical properties of the building block of silica nanowires, (SiO(2))(6), are investigated with the theory of atoms and molecules (QTAIM). Twenty-five conformers have been analyzed, ten of which have not been reported before. We extend the silica (SiO(2))(6) topology phase space using QTAIM; the Poincaré-Hopf topological sum rules are applied and used to identify the spanning set of topologies, and this includes finding eight new distinct topologies that satisfy the Poincaré-Hopf relation. A simple phase diagram of the solutions of the Poincaré-Hopf relation is created with the aid of a new classification scheme to determine the boundary between topological stability and instability. Sum rules are then found to be applicable to any set of isomers. We determine that O-O bonding interactions exist for the silica (SiO(2))(6) conformers in regions where the energy surface is flattest. In addition, we identify unstable local minima in the topology of the charge density in order to further compare conformer instabilities. We quantify the dimensionality of a molecule using the Poincaré-Hopf relation instead of Euclidean geometry. This quantum topological definition of geometry shows that the four most energetically stable (SiO(2))(6) conformers are quantified as two-dimensional within the new quantum topology.


Assuntos
Teoria Quântica , Dióxido de Silício/química , Modelos Moleculares , Estereoisomerismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-33638073

RESUMO

In this study, a novel ternary catalyst Mn-Fe-Ce/Al2O3 was synthesized by co-impregnation method, and was characterized by XRD, SEM, XPS, and FTIR. The catalytic performance of this ternary catalyst was evaluated in the heterogeneous catalytic ozonation of phenol pollutants and it improved the removal rate and mineralization degree of phenol pollutants. The changes of dissolved ozone in water and the TBA experiment proved that the ternary catalyst could accelerate the decomposition of ozone into hydroxyl radicals, thus accelerating the oxidation of phenol. Phosphate experiments and surface hydroxyl density measurements proved that surface hydroxyl was the active site of the catalyst. XPS analysis showed that the ternary catalysts accelerated electron transfer through the redox cycles of Mn2+-Mn3+-Mn4+, Fe2+-Fe3+, and Ce3+-Ce4+, which also contributed to the high catalytic activity. Moreover, the catalyst maintained high catalytic activity after five cycles of use. Therefore, the ternary catalyst was considered an efficient and promising catalyst for catalytic ozonation system.

18.
RSC Adv ; 11(6): 3585-3595, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35747695

RESUMO

Herein, we investigated catalytic potential of a functionalized porous organic polymer bearing sulfonic acid groups (PDVTA-SO3H) to the etherification of 5-hydroxymethylfurfural (HMF) to 5-ethoxymethylfurfural (EMF) under solvent-free conditions. The PDVTA-SO3H material was synthesized via post-synthetic sulfonation of the porous co-polymer poly-divinylbenzene-co-triallylamine by chlorosulfonic acid. The physicochemical properties of the PDVTA-SO3H were characterized by FT-IR, SEM, TG-DTG, and N2 adsorption isotherm techniques. PDVTA-SO3H had high specific surface area (591 m2 g-1) and high density of -SO3H group (2.1 mmol g-1). The reaction conditions were optimized via Box-Behnken response surface methodology. Under the optimized conditions, the PDVTA-SO3H catalyst exhibited efficient catalytic activity with 99.8% HMF conversion and 87.5% EMF yield within 30 min at 110 °C. The used PDVTA-SO3H catalyst was readily recovered by filtration and remained active in recycle runs.

19.
ChemistryOpen ; 10(4): 477-485, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33908700

RESUMO

A series of tetraimidazolium salts with different anions was prepared and applied in the isomerization of ß-pinene oxide. After examining the activity of different catalysts, a remarkable enhancement of the selectivity of perillyl alcohol (47 %) was obtained over [PEimi][HNO3 ]4 under mild reaction conditions and using DMSO as the solvent. Furthermore, noncovalent interactions between solvent molecules and the catalyst were found by FT-IR spectroscopy and confirmed by computational chemistry. The homogeneous catalyst showed excellent stability and was reused up to six times without significant loss.

20.
J Am Chem Soc ; 132(26): 8900-2, 2010 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-20540581

RESUMO

A new, efficient Cu-catalyzed intramolecular C-H oxidation/acylation method has been developed for the synthesis of substituted indoline-2,3-diones (isatins). In the presence of CuCl(2) and O(2), a variety of formyl-N-arylformamides underwent the tandem reaction to afford the corresponding indoline-2,3-diones in moderate to good yields. It is noteworthy that the reaction serves as the first example of transition-metal-catalyzed transformation for the preparation of indoline-2,3-diones.


Assuntos
Carbono/química , Cobre/química , Formamidas/química , Hidrogênio/química , Indóis/química , Acilação , Catálise , Oxirredução
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