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1.
J Am Chem Soc ; 146(25): 17438-17445, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38860872

RESUMO

Metal-organic polyhedra (MOPs) can exhibit tunable porosity and functionality, suggesting potential for applications such as molecular separations. MOPs are typically constructed by the bottom-up multicomponent self-assembly of organic ligands and metal ions, and the final functionality can be hard to program. Here, we used trianglsalen macrocycles as preorganized building blocks to assemble octahedral-shaped MOPs. The resultant MOPs inherit most of the preorganized properties of the macrocyclic ligands, including their well-defined cavities and chirality. As a result, the porosity in the MOPs could be tuned by modifying the structure of the macrocycle building blocks. Using this strategy, we could systematically enlarge the size of the MOPs from 26.3 to 32.1 Å by increasing the macrocycle size. The family of MOPs shows experimental surface areas of up to 820 m2/g, and they are stable in water. One of these MOPs can efficiently separate the rare gases Xe from Kr because the prefabricated macrocyclic windows of MOPs can be modified to sit at the Xe/Kr size cutoff range.

2.
ACS Omega ; 9(19): 21164-21173, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38764631

RESUMO

In this work, thermo-oxidative behavior, kinetic triplet, and free radical mechanism of ultraheavy oil during an in situ combustion (ISC) process were systematically surveyed via multiple thermal analysis techniques (TG/DTG/DSC/PDSC), model-free methods, and related mathematical simulation. First, specific mass loss, exothermic intensity, and corresponding temperature intervals were respectively determined in low-/high-temperature oxidation (LTO/HTO) regions. In addition, the comparison of atmospheric/pressurized differential scanning calorimetry (DSC/PDSC) experiments indicated that the pressurized conditions could obviously strengthen the oxidation progress with more heat emission. Then two model-free methods were contrastively employed for PDSC data to calculate LTO and HTO activation energy variations with the conversion rate. Moreover, the acceleratory rate model for LTO and the Sestak-Berggren model for HTO were accordingly picked as the most probable mechanism functions, which were later used to determine the simulated curves. Then, the simulations of α-T and dα/dT-T curves were respectively attained using Friedman equation in MATLAB software and contrasted with experimental data to validate the accuracy of the yielded kinetic triplet and forecast the combustion behavior. Further, the evolution pathways of the underlying oxidation mechanism was illustrated. This study updates the understanding of the nonisothermal combustion process, contributing to the subsequent numerical simulation and feasible investigation for in situ combustion implementation to enhance heavy oil recovery.

3.
Mycologia ; 116(3): 431-448, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38417055

RESUMO

Agaricus is a species-rich genus with more than 600 species around the world. In this work, three new species, Agaricus cacainus, A. baiyunensis, and A. praeclarefibrillosus are described from the specimens collected at Baiyun Mountain, Guangzhou, China, a subtropical area with a monsoon maritime climate, based on phylogenetic analyses and morphological examinations of internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), D1/D2 domains of the large subunit of ribosomal DNA (28S), and a part of translation elongation factor 1-alpha (TEF1). Agaricus cacainus in A. sect. Amoeni is characterized by a parabolic to applanate, slightly depressed pileus covered with chocolate brown, appressed, triangular squamules against white background, a white, furfuraceous stipe, an unchanging context when cut, a fragile and evanescent annulus, usually 4- or 2-spored basidia, and mostly pyriform cheilocystidia. Agaricus baiyunensis in A. sect. Minores has a pileus with a slightly truncate top covered with light brown, downy-wooly fibrillose scales and a light yellowish stipe with membranous annulus. Agaricus praeclarefibrillosus in A. sect. Brunneopicti is characterized by a pileus surface with brownish, triangular, recurved scales and longitudinally splitting lines toward margin, a cottony stipe with white, tiny, recurved fibrils, a single annulus, and variously shaped cheilocystidia, with sparsely ornamented basidiospores. The detailed comparison of their morphological characteristics with closely related species is provided.


Assuntos
Agaricus , DNA Fúngico , DNA Espaçador Ribossômico , Filogenia , China , Agaricus/classificação , Agaricus/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Análise de Sequência de DNA , Esporos Fúngicos/citologia , Esporos Fúngicos/classificação , RNA Ribossômico 28S/genética , Fator 1 de Elongação de Peptídeos/genética , Dados de Sequência Molecular
4.
Pharmaceuticals (Basel) ; 16(11)2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-38004434

RESUMO

Indiscriminate drug administration may lead to drug therapy results with varying effects on patients, and the proposal of personalized medication can help patients to receive effective drug therapy. Conventional ways of personalized medication, such as pharmacogenomics and therapeutic drug monitoring (TDM), can only be implemented from a single perspective. The development of pharmacometabolomics provides a research method for the realization of precise drug administration, which integrates the environmental and genetic factors, and applies metabolomics technology to study how to predict different drug therapeutic responses of organisms based on baseline metabolic levels. The published research on pharmacometabolomics has achieved satisfactory results in predicting the pharmacokinetics, pharmacodynamics, and the discovery of biomarkers of drugs. Among them, the pharmacokinetics related to pharmacometabolomics are used to explore individual variability in drug metabolism from the level of metabolism of the drugs in vivo and the level of endogenous metabolite changes. By searching for relevant literature with the keyword "pharmacometabolomics" on the two major literature retrieval websites, PubMed and Web of Science, from 2006 to 2023, we reviewed articles in the field of pharmacometabolomics that incorporated pharmacokinetics into their research. This review explains the therapeutic effects of drugs on the body from the perspective of endogenous metabolites and pharmacokinetic principles, and reports the latest advances in pharmacometabolomics related to pharmacokinetics to provide research ideas and methods for advancing the implementation of personalized medication.

5.
Angew Chem Int Ed Engl ; 61(32): e202202450, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35687266

RESUMO

Porous materials that contain ultrafine pore apertures can separate hydrogen isotopes via kinetic quantum sieving (KQS). However, it is challenging to design materials with suitably narrow pores for KQS that also show good adsorption capacities and operate at practical temperatures. Here, we investigate a metal-organic cage (MOC) assembled from organic macrocycles and ZnII ions that exhibits narrow windows (<3.0 Å). Two polymorphs, referred to as 2α and 2ß, were observed. Both polymorphs exhibit D2 /H2 selectivity in the temperature range 30-100 K. At higher temperature (77 K), the D2 adsorption capacity of 2ß increases to about 2.7 times that of 2α, along with a reasonable D2 /H2 selectivity. Gas sorption analysis and thermal desorption spectroscopy suggest a gate-opening effect of the MOCs pore aperture. This promotes KQS at temperatures above liquid nitrogen temperature, indicating that MOCs hold promise for hydrogen isotope separation in real industrial environments.

6.
ACS Appl Mater Interfaces ; 13(39): 47118-47126, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34570486

RESUMO

The synthesis and functionalization of porous organic cages (POCs) for separation have attracted growing interest over the past decade. However, the potential of solid-phase POCs for practical, large-scale separations will require incorporation into appropriate gas-solid or liquid-solid contactors. Contactors with more effective mass transfer properties and lower pressure drops than pelletized systems are preferred. Here, we prepared and characterized fiber sorbents with POCs throughout a cellulose acetate (CA) polymer matrix, which were then deployed in model separations. The POC CC3 was shown to be stable after exposure to spinning solvents, as confirmed by NMR, powder X-ray diffraction, and gas sorption experiments. CC3-CA fibers were spun using the dry-jet wet-quench spinning method. Spun fibers retained the adsorptive properties of CC3 powders, as confirmed by CO2 and N2 physisorption and TGA, reaching upward of 60 wt % adsorbent loading, whereas the pelletized CC3 counterparts suffered significant losses in textural properties. The separation capabilities of the CC3-CA fibers are tested with both simulated postcombustion flue gas and with Xe/Kr mixtures. Fixed bed breakthrough experiments performed on fibers samples show that CC3 embedded in polymeric fibers can effectively perform these proof-of-concept gas separations. The development of fiber sorbents embedded with POCs provides an alternative to traditional pelletization for the incorporation of these materials into adsorptive separation systems.

7.
Chem Commun (Camb) ; 57(50): 6141-6144, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34042126

RESUMO

Macrocycles are usually non-porous or barely porous in the solid-state because of their small intrinsic cavity sizes and tendency to close-pack. Here, we use a heterochiral pairing strategy to introduce porosity in a trianglimine macrocycle, by co-crystallising two macrocycles with opposing chiralities. The stable racemic trianglimine crystal contains an interconnected pore network that has a Brunauer-Emmett-Teller (BET) surface area of 355 m2 g-1.

8.
Angew Chem Int Ed Engl ; 60(32): 17556-17563, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-33979473

RESUMO

We report the first experimental investigation of porous organic cages (POCs) for the demanding challenge of SO2 capture. Three structurally related N-containing cage molecular materials were studied. An imine-functionalized POC (CC3) showed modest and reversible SO2 capture, while a secondary-amine POC (RCC3) exhibited high but irreversible SO2 capture. A tertiary amine POC (6FT-RCC3) demonstrated very high SO2 capture (13.78 mmol g-1 ; 16.4 SO2 molecules per cage) combined with excellent reversibility for at least 50 adsorption-desorption cycles. The adsorption behavior was investigated by FTIR spectroscopy, 13 C CP-MAS NMR experiments, and computational calculations.

9.
Chemistry ; 27(41): 10589-10594, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-33929053

RESUMO

Ethyl acetate is an important chemical raw material and solvent. It is also a key volatile organic compound in the brewing industry and a marker for lung cancer. Materials that are highly selective toward ethyl acetate are needed for its separation and detection. Here, we report a trianglimine macrocycle (TAMC) that selectively adsorbs ethyl acetate by forming a solvate. Crystal structure prediction showed this to be the lowest energy solvate structure available. This solvate leaves a metastable, "templated" cavity after solvent removal. Adsorption and breakthrough experiments confirmed that TAMC has adequate adsorption kinetics to separate ethyl acetate from azeotropic mixtures with ethanol, which is a challenging and energy-intensive industrial separation.


Assuntos
Acetatos , Compostos Macrocíclicos , Solventes
10.
Angew Chem Int Ed Engl ; 60(13): 7148-7154, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33300645

RESUMO

Herein we report a linear ionic molecule that assembles into a supramolecular nano-tunnel structure through synergy of trident-type ionic interactions and π-π stacking interactions. The nano-tunnel crystal exhibits anisotropic guest adsorption behavior. The material shows good thermal stability and undergoes multi-stage single-crystal-to-single-crystal phase transformations to a nonporous structure on heating. The material exhibits a remarkable chemical stability under both acidic and basic conditions, which is rarely observed in supramolecular organic frameworks and is often related to structures with designed hydrogen-bonding interactions. Because of the high polarity of the tunnels, this molecular crystal also shows a large CO2 -adsorption capacity while excluding other gases at ambient temperature, leading to high CO2 /CH4 selectivity. Aggregation-induced emission of the molecules gives the bulk crystals vapochromic properties.

11.
Xenobiotica ; 50(8): 980-987, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32072840

RESUMO

LLC-1903, a novel anticancer compound, was synthesized by optimizing the structure, which was derived from altering the leaving group of lobaplatin. It has an excellent in vitro anti-cancer activity, high water solubility, high stability in solution and low in vivo toxicity according to our former study.The plasma pharmacokinetics (PK) and tissue distribution of LLC-1903 and lobaplatin in rats were determined after intravenous administration of a single dose (0.06 mmol/kg body weight). Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the concentration of platinum (Pt) in plasma and tissue samples.Most PK parameters of the Pt in LLC-1903 showed a significant difference from those of lobaplatin. The plasma level of LLC-1903 is only half of that of lobaplatin (p < 0.01) which could be the direct result of faster drug clearance. The tissue distribution showed that both LLC-1903 and lobaplatin were mainly found in the liver and kidney, and less in other organs. At four time points (0.083, 0.5, 1 and 4 h) after administration, the tissue concentrations of LLC-1903 were almost always significantly higher than those of lobaplatin (p < 0.05 or p < 0.01).


Assuntos
Antineoplásicos/farmacocinética , Compostos de Platina/farmacocinética , Administração Intravenosa , Animais , Taxa de Depuração Metabólica , Distribuição Tecidual
12.
Chemosphere ; 241: 125022, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31627106

RESUMO

An efficient heterogeneous photocatalytic process coupling photocatalysis and Fenton-like process was carried out, where the Fenton-like cycle could be driven by self-produced H2O2 rather than extra H2O2 addition. It was revealed that C3N4por exhibited good performance at H2O2 production in pure water, which was enhanced up to eight times than bare g-C3N4. Fenton-like cycle was constructed in Ti3+-TiO2-C3N4por as C3N4por severed as H2O2 donator, while the Ti3+-TiO2 was able to provide photoinduced electrons for the Fenton-like process, resulting in the generation of much more OH radical. In addition, ESR spectra were performed to confirm the promotion of the Fenton-like cycle and much more OH radical was detected in Ti3+-TiO2-C3N4por than Ti3+-TiO2-C3N4 due to the great improvement in H2O2 production of C3N4por. What's more, the feasible photocatalytic mechanism of Ti3+-TiO2-C3N4por composite was also proposed.


Assuntos
Peróxido de Hidrogênio/química , Processos Fotoquímicos , Titânio/química , Catálise
13.
Small ; 16(5): e1905736, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31867884

RESUMO

Although silicon-based materials are ideal candidate anodes for high energy density lithium-ion batteries, the large volumetric expansion seriously damages the integrity of the electrodes and impedes commercial processes. Reasonable electrode design based on adjustable structures of silicon and strong binders prepared by a facile method is still a great challenge. Herein, a three-pronged collaborative strategy via hollow nanocubes, amorphous Void@SiOx @C, and in situ cross-linked polyacrylic acid and d-sorbitol 3D network binder (c-PAA-DS) is adopted to maintain structural/electrode integrality and stability. The all-integrated c-PAA-DS/Void@SiOx @C electrode delivers excellent mechanical property, which is attributed to ductility of the c-PAA-DS binder and high adhesion energy between Void@SiOx @C and c-PAA-DS calculated by density functional theory. Benefiting from the synergistic effect of accommodation of the hollow structure, protection of outer carbon shell, amorphous Void@SiOx @C, and strong adhesive c-PAA-DS binder, c-PAA-DS/Void@SiOx @C shows excellent electrochemical performance. Long cycling stability with a reversible capacity of 696 mAh g-1 is obtained, as well as tiny capacity decay after 500 cycles at 0.5 A g-1 and high-rate performance. The prelithiated Void@SiOx @C||LiNi0.5 Co0.2 Mn0.3 O2 (NCM523) full cell is also assembled and shows a reversible capacity of 157 mAh g-1 at 0.5 C, delivering an excellent capacity retention of 94% after 160 cycles.

14.
Science ; 366(6465): 613-620, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31672893

RESUMO

The separation of hydrogen isotopes for applications such as nuclear fusion is a major challenge. Current technologies are energy intensive and inefficient. Nanoporous materials have the potential to separate hydrogen isotopes by kinetic quantum sieving, but high separation selectivity tends to correlate with low adsorption capacity, which can prohibit process scale-up. In this study, we use organic synthesis to modify the internal cavities of cage molecules to produce hybrid materials that are excellent quantum sieves. By combining small-pore and large-pore cages together in a single solid, we produce a material with optimal separation performance that combines an excellent deuterium/hydrogen selectivity (8.0) with a high deuterium uptake (4.7 millimoles per gram).

15.
Radiat Prot Dosimetry ; 187(1): 88-97, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31135899

RESUMO

A comparison of Geant4 physics lists is conducted in the calculation of the total absorbed dose, boron dose, and non-boron dose in phantom, and the total depth-dose, boron depth-dose, and non-boron depth-dose along the beam axis for neutrons in a range of 0.0253 eV to 10 MeV. Physics processes are included for neutrons, photons, and charged particles, and calculations are conducted for neutrons and secondary particles. The results obtained from QBBC, QGSP_BERT, and neutron high precision physics lists with and without S(α, ß) data are compared with the FLUKA values. Neutron high precision physics lists with S(α, ß) data showed the best agreement with FLUKA in the studied energy range.


Assuntos
Terapia por Captura de Nêutron de Boro/métodos , Boro , Nêutrons , Imagens de Fantasmas , Fótons , Radiometria/métodos , Simulação por Computador , Humanos , Física , Dosagem Radioterapêutica
16.
Nanomicro Lett ; 11(1): 96, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34138034

RESUMO

Potassium-ion batteries (KIBs) are a potential candidate to lithium-ion batteries (LIBs) but possess unsatisfactory capacity and rate properties. Herein, the metallic cobalt selenide quantum dots (Co0.85Se-QDs) encapsulated in mesoporous carbon matrix were designed via a direct hydrothermal method. Specifically, the cobalt selenide/carbon composite (Co0.85Se-QDs/C) possesses tertiary hierarchical structure, which is the primary quantum dots, the secondary petals flake, and the tertiary hollow micropolyhedron framework. Co0.85Se-QDs are homogenously embedded into the carbon petals flake, which constitute the hollow polyhedral framework. This unique structure can take the advantages of both nanoscale and microscale features: Co0.85Se-QDs can expand in a multidimensional and ductile carbon matrix and reduce the K-intercalation stress in particle dimensions; the micropetals can restrain the agglomeration of active materials and promote the transportation of potassium ion and electron. In addition, the hollow carbon framework buffers volume expansion, maintains the structural integrity, and increases the electronic conductivity. Benefiting from this tertiary hierarchical structure, outstanding K-storage performance (402 mAh g-1 after 100 cycles at 50 mA g-1) is obtained when Co0.85Se-QDs/C is used as KIBs anode. More importantly, the selenization process in this work is newly reported and can be generally extended to prepare other quantum dots encapsulated in edge-limited frameworks for excellent energy storage.

17.
Med Sci Monit ; 24: 8391-8400, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30459299

RESUMO

BACKGROUND The aims of this study were to investigate the expression of methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) in human tissue containing clear cell renal cell carcinoma (CCRCC) compared with normal renal tissue, and the effects of upregulating the expression of MTHFD1 in the human CCRCC cell line, Caki-1. MATERIAL AND METHODS Tumor and adjacent normal renal tissue were obtained from 44 patients who underwent radical nephrectomy for CCRCC. Caki-1 human CCRCC cells were divided into the control group, the empty vector (EV) group, and the plasmid-treated group that overexpressed MTHFD1. MTHFD1 mRNA and protein levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. The cell counting kit-8 (CCK-8) assay measured cell viability. Flow cytometry evaluated apoptosis and the cell cycle. Western blot measured the protein levels of MTHFD1, Bax, Bcl-2, Akt, p53, and cyclin D1, and qRT-PCR determined the gene expression profiles. RESULTS MTHFD1 mRNA and protein levels in CCRCC tumor tissues were significantly lower compared with adjacent normal renal tissue. MTHFD1 over-expression in Caki-1 cells inhibited cell proliferation, arrested cells in the G1 phase, increased cell apoptosis, and upregulated gene and protein expression of Bax/Bcl-2 and p53 and inhibited p-Akt, and cyclin D1. CONCLUSIONS MTHFD1 was underexpressed in CCRCC tissue when compared with normal renal tissue. MTHFD1 transfection of human CCRCC Caki-1 cells in vitro inhibited cell proliferation and promoted apoptosis, associated with reduced expression of cyclin D1, reduced Akt phosphorylation, and increased expression of Bax/Bcl-2 and p53.


Assuntos
Carcinoma de Células Renais/enzimologia , Neoplasias Renais/enzimologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/biossíntese , Antígenos de Histocompatibilidade Menor/biossíntese , Apoptose/fisiologia , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Ciclina D1/biossíntese , Ciclina D1/genética , Ciclina D1/metabolismo , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/biossíntese , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcriptoma , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/biossíntese , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
18.
Adv Sci (Weinh) ; 5(10): 1800782, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30356990

RESUMO

Due to the abundant and low-cost K resources, the exploration of suitable materials for potassium-ion batteries (KIBs) is advancing as a promising alternative to lithium-ion batteries. However, the large-sized and sluggish-kinetic K ions cause poor battery behavior. This work reports a metallic octahedral CoSe2 threaded by N-doped carbon nanotubes as a flexible framework for a high-performance KIBs anode. The metallic property of CoSe2 together with the highly conductive N-doped carbon nanotubes greatly accelerates the electron transfer and improves the rate performance. The carbon nanotube framework serves as a backbone to inhibit the agglomeration, anchor the active materials, and stabilize the integral structure. Every octahedral CoSe2 particle arranges along the carbon nanotubes in sequence, and the zigzag void space can accommodate the volume expansion during cycling, therefore boosting the cycling stability. Density functional theory is also employed to study the K-ion intercalation/deintercalation process. This unique structure delivers a high capacity (253 mAh g-1 at 0.2 A g-1 over 100 cycles) and enhanced rate performance (173 mAh g-1 at 2.0 A g-1 over 600 cycles) as an advanced anode material for KIBs.

19.
Chemosphere ; 210: 334-340, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30007187

RESUMO

γ-FeOOH was grown in situ on the surface of rod Bi2O3 to construct a perfect cycle coupling photocatalysis and heterogeneous Fenton-like process. The degradation efficiency of this system was detected under the irradiation of visible light. γ-FeOOH/Bi2O3 showed better degradation efficiency than pure Bi2O3 and γ-FeOOH, and the amount of TOC was decreased to 4.3, suggesting that the system exhibits outstanding oxidation ability that MO and phenol could be degraded to CO2 and H2O totally. PL spectra, trapping experiments and ESR test were also carried out to confirm the mechanism of photocatalysis with heterogeneous Fenton-like process, and the suitable conduction band (CB) of Bi2O3 matches the electric potential of iron ions was proved to be the key to keep the perfect cycle. Then optimal concentration of H2O2, the effect of pH and the stability of the photocatalyst were also investigated.


Assuntos
Bismuto/química , Compostos Férricos/química , Peróxido de Hidrogênio/química , Ferro/química , Fotólise , Catálise , Oxirredução
20.
R Soc Open Sci ; 5(4): 172364, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29765683

RESUMO

Cu-ZSM-5 catalysts were prepared by chemical vapour deposition for catalytic wet peroxide oxidation (CWPO) of phenol in a fixed bed reactor. Firstly, Cu-ZSM-5 catalysts with Cu loading of 0.5, 2, and 6 wt% were prepared and characterized by X-ray diffraction (XRD), N2 adsorption-desorption and X-ray photoelectron spectra (XPS). The characterization results demonstrated that CuO was uniformly dispersed on ZSM-5 with slight effect on the structure properties of the support. Then, several variables, such as the copper loading, reaction temperature, catalyst bed height and feed flow rate were investigated in the CWPO of phenol in aqueous solution at high concentration (1000 ppm). Compared with the catalyst prepared by the impregnation method, the Cu-ZSM-5 prepared by chemical vapour deposition has a better capacity of further oxidizing the intermediate organic products into carbon dioxide and water with less metal loading. Based on the Cu-ZSM-5 catalyst with Cu loading of 6 wt%, complete removal of phenol and a high TOC reduction (around 70%) have been achieved at the temperature of 80°C feed flow rate of 2 ml min-1 and catalyst bed height of 3 cm. Moreover, this catalyst maintained high catalytic activity after three runs with high phenol conversion (94%) under this optimum operating condition. Finally, the reaction mechanism was studied based on the intermediates detected by high-performance liquid chromatography (HPLC).

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