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1.
J Colloid Interface Sci ; 663: 280-286, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38402822

RESUMO

Amorphous engineering and atomistic doping provide an effective way to improve the catalytic activity in the oxygen evolution reaction (OER) of transition metal layered double hydroxides. Herein, Cerium (Ce) was introduced into NiFe-based oxyhydroxide using a modified aqueous sol-gel procedure. Ce as an electron acceptor promoted the coupling oxidation of Ni2+/3+ in NiFe oxyhydroxide, and the activated oxyhydroxide showed excellent catalytic activity in OER. The amorphous NiFeCe oxyhydroxide electrocatalyst demonstrated great modified OER catalytic activity under alkaline conditions and excellent cyclic stability, with an overpotential of only 284 mV at 50 mA cm-2, which was significantly better than amorphous NiFe oxyhydroxide and crystalline NiFeCe oxyhydroxide. Theoretical investigations further indicated that the overpotential of the rate-determining step (*OOH deprotonation) decreased from 0.66 to 0.41 V after Ce doping and strong electron interaction, effectively reducing the dependence of proton activity in the solution of OER, and optimizing the adsorption/desorption process of related oxygen-containing species in the reaction. This work also provides a good reference for optimizing OER activity by using rare-earth-metal induced electronic regulation strategies.

2.
Molecules ; 29(4)2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38398523

RESUMO

The efficiency and performance of proton exchange membrane fuel cells (PEMFCs) are primarily influenced by ORR electrocatalysts. In recent years, atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have gained significant attention due to their high active center density, high atomic utilization, and high activity. These catalysts are now considered the preferred alternative to traditional noble metal electrocatalysts. The unique properties of M-N-C catalysts are anticipated to enhance the energy conversion efficiency and lower the manufacturing cost of the entire system, thereby facilitating the commercialization and widespread application of fuel cell technology. This article initially delves into the origin of performance and degradation mechanisms of Fe-N-C catalysts from both experimental and theoretical perspectives. Building on this foundation, the focus shifts to strategies aimed at enhancing the activity and durability of atomically dispersed Fe-N-C catalysts. These strategies encompass the use of bimetallic atoms, atomic clusters, heteroatoms (B, S, and P), and morphology regulation to optimize catalytic active sites. This article concludes by detailing the current challenges and future prospects of atomically dispersed Fe-N-C catalysts.

3.
Molecules ; 29(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38276614

RESUMO

Proton Exchange Membrane Water Electrolysis (PEMWE) under acidic conditions outperforms alkaline water electrolysis in terms of less resistance loss, higher current density, and higher produced hydrogen purity, which make it more economical in long-term applications. However, the efficiency of PEMWE is severely limited by the slow kinetics of anodic oxygen evolution reaction (OER), poor catalyst stability, and high cost. Therefore, researchers in the past decade have made great efforts to explore cheap, efficient, and stable electrode materials. Among them, the RuO2 electrocatalyst has been proved to be a major promising alternative to Ir-based catalysts and the most promising OER catalyst owing to its excellent electrocatalytic activity and high pH adaptability. In this review, we elaborate two reaction mechanisms of OER (lattice oxygen mechanism and adsorbate evolution mechanism), comprehensively summarize and discuss the recently reported RuO2-based OER electrocatalysts under acidic conditions, and propose many advanced modification strategies to further improve the activity and stability of RuO2-based electrocatalytic OER. Finally, we provide suggestions for overcoming the challenges faced by RuO2 electrocatalysts in practical applications and make prospects for future research. This review provides perspectives and guidance for the rational design of highly active and stable acidic OER electrocatalysts based on PEMWE.

4.
Molecules ; 28(24)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38138550

RESUMO

PEDOT-Ag/AgCl is a highly promising material with dual functions of hydrogen evolution reaction (HER) and supercapacitors. In this study, a simple low-temperature stirring and light irradiation method was used to synthesize PEDOT-Ag/AgCl on the surface. Then, PEDOT-Ag/AgCl was analyzed using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. PEDOT-Ag/AgCl reacted in 1 M KOH alkaline electrolyte with an overpotential of 157 mV at 20 mA·cm-2 and a Tafel slope of 66.95 mv·dec-1. Owing to the synergistic effect of PEDOT and Ag/AgCl, this material had a small resistance (1.7 Ω) and a large specific capacitance (978 F·g-1 at current density of 0.5 A·g-1). The synthesis method can prepare nanostructured PEDOT with uniformly-distributed Ag nanoparticles and rod-shaped AgCl on the surface, which can be used as both HER electrocatalysts and supercapacitor electrodes.

5.
Molecules ; 28(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37894519

RESUMO

Single-atom catalysts anchored to oxide or carbonaceous substances are typically tightly coordinated by oxygen or heteroatoms, which certainly impact their electronic structure and coordination environment, thereby affecting their catalytic activity. In this study, we prepared a stable oxygen evolution reaction (OER) catalyst on tungsten carbide using a simple pyrolysis method. The unique structure of tungsten carbide allows the atomic RuNi catalytic site to weakly bond to the surface W and C atoms. XRD patterns and HRTEM images of the WCx-RuNi showed the characteristics of phase-pure WC and W2C, and the absence of nanoparticles. Combined with XPS, the atomic dispersion of Ru/Ni in the catalyst was confirmed. The catalyst exhibits excellent catalytic ability, with a low overpotential of 330 mV at 50 mA/cm2 in 1 m KOH solutions, and demonstrates high long-term stability. This high OER activity is ascribed to the synergistic action of metal Ru/Ni atoms with double monomers. The addition of Ni increases the state density of WCx-RuNi near the Fermi level, promoting the adsorption of oxygen-containing intermediates and enhancing electron exchange. The larger proximity of the d band center to the Fermi level suggests a strong interaction between the d electrons and the valence or conduction band, facilitating charge transfer. Our research offers a promising avenue for reasonable utilization of inexpensive and durable WCx carrier-supported metal single-atom catalysts for electrochemical catalysis.

6.
J Colloid Interface Sci ; 648: 440-447, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37302227

RESUMO

The atomically-dispersed and nitrogen-coordinated iron (FeNC) on a carbon catalyst is a potential non-noble metal catalyst that can replace precious metal electrocatalysts. However, its activity is often unsatisfactory owing to the symmetric charge distribution around the iron matrix. In this study, atomically- dispersed Fe-N4 and Fe nanoclusters loaded with N-doped porous carbon (FeNCs/FeSAs-NC-Z8@34) were rationally fabricated by introducing homologous metal clusters and increasing the N content of the support. FeNCs/FeSAs-NC-Z8@34 exhibited a half-wave potential of 0.918 V, which exceeded that of the commercial benchmark Pt/C catalyst. Theoretical calculations verified that introducing Fe nanoclusters can break the symmetric electronic structure of Fe-N4, thus inducing charge redistribution. Furthermore, it can optimize a part of Fe 3d occupancy orbitals and accelerate OO fracture in OOH* (rate-determining step), thus significantly improving oxygen reduction reaction activity. This work provides a reasonably advanced pathway to modulate the electronic structure of the single-atom center and optimize the catalytic activity of single-atom catalysts.

7.
Front Chem ; 10: 969905, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36092675

RESUMO

Exploring durable and highly-active non-noble-metal nanomaterials to supersede Pt-based nanomaterials is an effective way, which can reduce the cost and boost the catalytic efficiency of oxygen reduction reaction (ORR). Herein, we constructed atomically-dispersed Mn atoms on the ZIF-derived nitrogen-doped carbon frameworks (Mn-Nx/NC) by stepwise pyrolysis. The Mn-Nx/NC relative to pure nitrogen-doped carbon (NC) exhibited superior electrocatalytic activity with a higher half-wave potential (E 1/2 = 0.88 V) and a modest Tafel slope (90 mV dec-1) toward ORR. The enhanced ORR performance of Mn-Nx/NC may be attributed to the existence of Mn-Nx active sites, which can more easily adsorb intermediates, promoting the efficiency of ORR. This work provides a facile route to synthesize single-atom catalysts for ORR.

8.
J Colloid Interface Sci ; 627: 215-223, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35849855

RESUMO

Exploring highly active and inexpensive electrocatalysts for oxygen evolution reaction (OER) is considered to be one of the preconditions for the development of energy and environment-related technologies. Nickel-based layered double hydroxides (LDHs) are extensively-studied OER electrocatalysts, but they still require relatively high overpotentials to achieve threshold current densities. In this work, iron-doped nickel-vanadium hydroxide microspheres (Fe-doped NiV HMS) were synthesized by doping iron ions into the NiV HMS through a facile cation-exchange method. The Fe-doped NiV HMS are hollow hierarchical structure stacked by high-density perpendicularly-lying nanosheets, which provide enough space for electrolyte penetration and diffusion. Owing to optimized composition and hollow hierarchical structure, the Fe-doped NiV HMS exhibits excellent electrocatalytic performance, which possessed a very low running overpotential (255 mV at 10 mA cm-2) and a smallest Tafel slope (56 mV dec-1) compared with hierarchical NiV HMS toward OER. Electrochemical results and density functional theory (DFT) manifest that Fe doping could regulate the electronic structure of NiV HMS, thus improving its electrical conductivity and electron transfer rate, and thus enhancing its catalytic activity. This research provides a convenient way to prepare Ni-based hydroxides as promising OER catalysts.

9.
ACS Appl Mater Interfaces ; 14(26): 29986-29992, 2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35758264

RESUMO

PGM-free (platinum group metal) electrocatalysts are intensively investigated and used as low-cost catalysts for the oxygen reduction reaction (ORR) in the field of fuel cells, but further studying their performance improvement methods and actual reaction mechanism is still a big a challenge. In this work, a novel eletrocatalyst containing atomically dispersed Mn/Fe single atoms (SAs) and Fe nanoparticles (NPs) on N-doped carbonaceous (nanosheet/nanotube hybrids) is fabricated via a simple pyrolysis method. This high-activity ORR electrocatalyst has higher half-wave potential (E1/2 = 0.91 V) and superior long-term durability in alkaline solutions and outperforms Pt/C catalysts, which can be ascribed to the synergetic interaction between Mn/Fe SAs and Fe-NPs. FeNPs/MnFeSAs-NC-25 has stronger reactant adsorption ability and a lower dissociation energy barrier than FeNPs/FeSAs-NC, which is conducive to breaking the O-O bond and accelerating ORR kinetics. This work presents a method to synthesize carbon-based electrocatalysts with high ORR activity and stability and shows that a variety of active sites encapsulated in N-doped carbonaceous materials can be a class of competitive candidates for PGM-free electrocatalysts.

10.
Front Chem ; 10: 849505, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35223776

RESUMO

Herein, we report the high Fischer-Tropsch synthesis performance of the Co-based catalysts supported on graphitized ordered mesoporous carbon (GMC-900) by using a facile strategy. Compared with CMK-3 and active carbon (AC), the obtained GMC-900 by using pollution-free soybean oil as a carbon source exhibited enhanced catalytic performance after loading Co species due to its highly crystallized graphitic structure and uniform dispersion of CoO. As a result, Co/GMC-900 was an effective catalyst with the maximum C5+ selectivity of 52.6%, which much outperformed Co/CMK-3 and Co/AC. This research provides an approach to produce advanced Co-based catalysts with satisfactory performance for efficient Fischer-Tropsch synthesis.

11.
J Colloid Interface Sci ; 616: 433-439, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35220190

RESUMO

Exploring highly-efficient noble-metal-free electrocatalysts for oxygen reduction reaction (ORR) is crucial for preparation of rechargeable metal-air batteries. Herein, FeNi-mIm (guest) was loaded on the surface of ZIF-8 (host) via a novel host-guest strategy, and the resulting ZIF-8@FeNi(mIm)X precursors can be converted to FeNi SAs/NC catalysts with controllable structures. Robust metal-organic framework (MOF)-derived atomically dispersed Fe/Ni dual single atom electrocatalysts for ORR were developed, followed by pyrolysis of the precursors. Characterizations showed that the atomically-dispersed Fe/Ni active sites were uniformly embedded in the N-doped carbon framework. As a result, the ORR performance was obviously improved with lower half-wave potential (E1/2 = 0.91 V) in alkaline media. Such improvement is mainly attributed to the synergy of fully-exposed bimetallic single atom active sites caused by the interaction of Fe/Ni 3d orbitals. The lower adsorption energy of intermediate hydroxyl groups on the active sites and the smaller ORR energy barrier were calculated by the density functional theory. The novelty FeNi SAs/NC catalysts showed faster ORR dynamics in the rate-determining step of four-electron transfer. The synthesis strategy reported here provides an efficient approach to construct high performance dual single-atom catalysts with fully-exposed active sites on the surface.

12.
J Biomater Sci Polym Ed ; 33(1): 20-34, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34602004

RESUMO

Combination therapy in cancer therapy has been widely used for its positive attributes, such as minimizing the undesirable side effects of chemotherapies and enhancing the therapeutic effects on different cancers. Compared with free drugs crizotinib (CRZ) and gemcitabine (GEM), CRZ@GEM-NPs could remarkably improve the cytotoxicity for endometrial cancer (EC) cells (Ishikawa cells and KLE cells) after treatment with MTT assay. In this study, CRZ and GEM were conjugated to tri-block copolymer poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, known as NPs). The fabricated nanoparticles were characterized by the high-resolution transmission electron microscopy (HR-TEM), and the particles size and zeta potential were investigated by the dynamic light scattering analysis. Further, the morphological features of the EC cell lines were examined by the biochemical staining assays. Morphological changes in endometrial cells morphology revealed by nuclear fragmentation and nuclear condensation (the hallmarks of apoptosis) were noted upon treatment with CRZ@GEM-NPs to the Ishikawa and KLE cancer cells. In addition, resulting in the highest ratio of apoptosis and mitochondrial membrane potential shows the cell death through the mitochondrial membrane potential. In vivo, systemic toxicity studies showed no histological changes and substantial blood biochemical with the near-normal appearance of the organs upon treatment with CRZ@GEM-NPs. Overall, the targeted combination suitable therapeutic framework may be a promising candidate for improved EC therapy.


Assuntos
Neoplasias do Endométrio , Nanopartículas , Crizotinibe , Desoxicitidina/análogos & derivados , Portadores de Fármacos , Neoplasias do Endométrio/tratamento farmacológico , Feminino , Humanos , Poliésteres , Polietilenoglicóis , Polímeros , Gencitabina
13.
ACS Omega ; 6(25): 16592-16599, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34235331

RESUMO

Catalytic activity and target product selectivity are strongly correlated to the size, crystallographic phase, and morphology of nanoparticles. In this study, waste lignin from paper pulp industry is employed as the carbon source, which is modified with carboxyl groups at the molecular level to facilitate anchoring of metals, and a new type of carbon-based catalyst was obtained after carbonization. As a result, the size of the metal particles is effectively controlled by the chelation between -COO- and Fe3+. Furthermore, Fe/CM-CL with a particle size of 1.5-2.5 nm shows excellent catalytic performance, the conversion of carbon monoxide reaches 82.3%, and the selectivity of methane reaches 73.2%.

14.
J Colloid Interface Sci ; 585: 800-807, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33121752

RESUMO

Metal-organic frameworks (MOFs)-derived catalysts exhibit highly-efficient hydrogen or oxygen evolution performance on water splitting. However, it is an urgent problem to construct bifunctional electrocatalysts for both hydrogen and oxygen evolution performance. Herein, we adopted Ag nanowires as templates to prepare one-dimensional Ag nanowire@ZIF-8@ZIF-67 precursors (1D AgNW@ZIF-8@ZIF-67). Through pyrolysis, AgNW@ZIF-8@ZIF-67 precursors transformed into nitrogen-doped carbon frameworks (NCF) embedded with zinc-cobalt (ZnCo) nanoparticles on the surface of Ag NWs (denoted as Ag@ZnCo/NCF nanohybrids). The nanohybrids were consisted of Ag NWs with good conductivity and ZnCo/NCF nanohybrids with rich accessible active sites. Benefiting from their large specific surface area, accessible active sites and synergistic effect among components, Ag@ZnCo/NCF nanohybrids exhibit lower overpotentials of 139 mV and 279 mV at the current density of 10 mA cm-2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution, severally. Compared with other catalysts, Ag@ZnCo/NCF nanohybrids possess smaller Tafel slope, indicating their higher catalytic activity. This work provides a new perspective for designing low-cost and highly efficient bifunctional electrocatalysts for overall water splitting.

15.
Oncol Lett ; 20(5): 275, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33014154

RESUMO

Ubiquitin-conjugating enzyme E2T (UBE2T) plays a significant role in carcinogenesis. Previous studies have demonstrated that UBE2T promotes the development and progression of numerous types of cancer. However, the association between UBE2T expression and colorectal cancer (CRC) remains unclear. In the present study, UBE2T protein expression was examined in the tissues of patients with CRC via immunohistochemistry. In addition, UBE2T expression data and corresponding clinical information were obtained from The Cancer Genome Atlas (TCGA). In the clinical samples, the associations between UBE2T expression and clinicopathological factors were evaluated by the χ2 or Fisher's exact tests. In TCGA data, associations between UBE2T expression and clinical characteristics were evaluated using a logistic regression model. Overall survival was analyzed using Kaplan-Meier and Cox regression analyses. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting assays were used to examine UBE2T expression in normal and CRC cell lines. Gene set enrichment analysis (GSEA) was performed on the dataset from TCGA. UBE2T protein was highly expressed in the cytoplasm of tumor cells in 29/50 clinical samples, whereas in the adjacent normal tissues, it was only highly expressed in 2/50 samples. Furthermore, UBE2T expression was associated with the N classification (P<0.001), clinical TNM stage (P<0.001) and histological grade of tumors (P=0.010). Survival analysis showed an association between high UBE2T expression and poor survival rate in patients with CRC (P=0.002). Cox regression analysis also revealed that UBE2T expression was an independent prognostic factor for these patients (P=0.006). RT-qPCR and western blotting showed that UBE2T was expressed in CRC cell lines at higher levels than that in a normal colon cell line. Analysis of TCGA data revealed that UBE2T was highly expressed in tumor samples compared with normal samples, but was not associated with prognosis. GSEA showed that high expression of UBE2T was associated with the Kyoto Encyclopedia of Genes and Genomes pathways 'cell cycle', 'oxidative phosphorylation', 'DNA replication', 'p53 signaling pathway', 'ubiquitin mediated proteolysis' and 'pentose phosphate pathway'. These results indicate that UBE2T may play an important role in the progression of CRC and serve as a potential prognostic factor during the treatment of cancer.

16.
J Colloid Interface Sci ; 577: 329-336, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32485414

RESUMO

Powerful yet orderly nanostructure lithium-ion batteries (LIBs) are eagerly desired to satisfy the practical application of portable electronics and smart grids. However, the surface re-stacking and surface functionalization on the MXenes in the anode electrode severely restrict the accessibility to electrolyte ions, hindering the full utilization of their intrinsic properties. To address this challenge, we rationally design three-dimensional (3D) Sn@Ti3C2 materials and fabricate them in a unique layer-by-layer manner through self-assembly for boosting LIBs. In this design system for fast lithium-ion storage, the Ti3C2 MXene nanosheets serving as 3D scaffolds buffer the severe volume expansion and agglomeration of Sn nanoparticles (NPs) and enhance electrode conductivity at the interface. Furthermore, Sn NPs are embedded as interlayer spacers to prevent nanosheet re-stacking and provide outstanding electrochemical performance. The nanostructure can increase the lithium-ion diffusion coefficient and create additional active sites. As a result, the Sn@Ti3C2 anode exhibits a superior specific capacity up to 666 mA∙h∙g-1 at 0.5 A∙g-1 after 250 cycles. Compared with pure Sn NPs, the improved electrochemical performance of Sn@Ti3C2 can be ascribed to the high electronic conductivity of Ti3C2 MXene nanosheets. The 3D Sn@Ti3C2 materials prepared in a layer-by-layer manner through self-assembly display promising performances for LIBs.

17.
J Nanosci Nanotechnol ; 19(9): 5736-5742, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30961732

RESUMO

Ag3PO4/sulfur-doped g-C3N4 heterojunctions were fabricated by the means of a facile calcination and co-precipitation method. Structural characterization suggested that Ag3PO4 was successfully loaded onto sulfur-doped g-C3N4. The absorption band edges of sulfur-doped g-C3N4 were shifted to the longer wavelength in comparison with bulk g-C3N4. The Ag3PO4/sulfur-doped g-C3N4 heterojunctions manifested substantially higher visible-light photocatalytic performance as compared with Ag3PO4/bulk g-C3N4. Photoluminescence spectra suggested that the stable Ag3PO4/SGCN heterojunctions could effectively address the electron-hole recombination rate, together with remarkably enhancing the photocatalytic activity. The enhancement of light absorption and better dispersion in Ag3PO4/sulfur-doped g-C3N4 provide more migration channels, together with posing crucial responsibility for the enhanced photocatalytic performance.

18.
J Colloid Interface Sci ; 532: 280-286, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30092510

RESUMO

Hydrogen generation photocatalyzed by low-cost graphite carbon nitride (g-C3N4) is a fascinating and effective route to solve energy crisis, but is mainly limited by the few reactive sites, low carrier separation efficiency and mediocre visible-light utilization. In this work, these limitations were tackled through a facile eco-friendly precursor pretreatment by tuning bulk g-C3N4 into porous structure. This pretreatment restricted agglomeration in the subsequent condensation and created more porous channels for charge carrier transfer and more surface active sites for reaction. The modified g-C3N4 has larger surface area, broader visible-light response, enhanced electron migration capacity and prolonged lifetime of photogenerated carriers. These well-amended g-C3N4 nanosheets possess an average hydrogen evolution rate 5.7 times that of bulk g-C3N4. This work affords a facile, eco-friendly and scalable strategy to design or synthesize other porous materials.

19.
J Colloid Interface Sci ; 516: 16-22, 2018 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-29408102

RESUMO

Mesoporous silica-encapsulated iron materials contribute to the suppression of self-aggregation and thereby enhances the Fischer-Tropsch synthesis activity. However, constructing Fe-based supported catalysts with high activity and selectivity in the Fischer-Tropsch synthesis to lower olefins (FTO) by a conventional mesoporous silica support has been proven challenging due to its low hydrothermal stability and low reducibility. Herein, we developed a core-shell Fe@SiO2-GC structure with an optimized interface of the catalyst by introducing graphitic carbon (GC) that weakened the Fe-SiO2 interaction. Transmission electron microscopy and nitrogen adsorption-desorption characterization proved GC-modified catalysts had well-defined core-shell structures. The Fe@SiO2-GC-2 containing the optimal GC content had the largest surface area and pore volume, and outperformed Fe2O3@SiO2 in terms of CO conversion (60.1%) and C2-C4 olefin selectivity (40.7%) within 100 h. The significant improvement of FTO performance was attributed to the rigid porous framework of GC, which allowed free access of syngas and inhibited mesoporous channel collapse during FTO, so the catalytic activity and stability were improved by the synergism between higher Fe dispersion and reducibility. Moreover, the narrow well-defined mesoporous channel also exerted a modest spatial restriction effect, which inhibited the formation of long-chain hydrocarbon and tailored the product distribution toward lower distillate, thus improving the selectivity toward C2-C4.


Assuntos
Alcenos/síntese química , Compostos Férricos/química , Grafite/química , Nanocompostos/química , Dióxido de Silício/química , Adsorção , Monóxido de Carbono/química , Catálise , Temperatura Alta , Nitrogênio/química , Oxirredução , Tamanho da Partícula , Porosidade , Propriedades de Superfície
20.
ACS Omega ; 3(1): 1350-1356, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-31457970

RESUMO

Bio-renewable lignin has been used as a carbon source for the preparation of porous carbon materials. Nevertheless, up to now, there are few studies about the influence of molecular weight of lignin on the structure and morphology of the ordered mesoporous carbon. Here, we synthesized the ordered mesoporous carbon derived from different molecular weights of lignin and Pluronic F127. Fortunately, we found that molecular weight is an important factor for obtaining highly ordered channels, high specific surface area, and ordered mesoporous carbon. More importantly, the narrow well-defined mesoporous channel could exert a spatial restriction effect to some extent, which can serve as nanoreactors for efficient reactions and enhance catalytic performance. The highly ordered mesoporous carbon from lignin is a good candidate for Fischer-Tropsch synthesis catalyst supports.

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