Reaction Kinetics Mechanisms and Catalysis
·
2021
·Vol. 134
·期 2
·777-792
·
IF 2.081
Liu Yingxin,Zhang Kaiyue,Zhang Liang,Wang Yun,Wei Zuojun
The selective reductive amination of levulinic acid (LA) into pyrrolidone derivatives is regarded as one of the most promising reactions in the fields of biomass conversion into high value-added chemicals. Herein, we report a one-pot synthesis of N -substituted-5-methyl-2-pyrrolidones by reductive amination of LA/ester with nitriles over several commercial catalysts. Among the catalysts texted, Pd/C was found to be the most efficient for the reductive amination of LA/ester with various nitriles to give high yields of pyrrolidones (up to 92%) under mild reaction conditions (80 °C, 1.6 MPa H 2 , tetrahydrofuran solvent). And the catalyst showed good reusability.
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CATALYSIS LETTERS
·
2021
·Vol. 153
·期 6
·1666-1675
·
IF 3.186
Wang Yuan,Liu Shanshan,Zhang Yidong,Guo Qirui
Hydrogenation of biomass-derived furfuryl alcohol to widely used tetrahydrofurfuryl alcohol is an important industrial route, which however calls for a more efficient catalyst. In this work, a highly selective and stable Ni-C-Al 2 O 3 catalyst for furfuryl alcohol hydrogenation to tetrahydrofurfuryl alcohol is reported. The catalyst precursor is prepared by in-situ growth of Ni-based metal organic frameworks (Ni-BTC) on Al 2 O 3 and then the precursor undergoes thermal decomposition to obtain the catalyst directly. For comparison, Ni-C/Al 2 O 3 acquired from pyrolysis of physically mixed Ni-MOFs with Al 2 O 3 and Ni/Al 2 O 3 prepared by impregnation method are also tested as the hydrogenation catalysts. The prepared catalysts are characterized by a series of techniques, including XRD, FT-IR, TG, TEM, SEM, XPS and BET to reveal the relationship between the catalysts structure and their performance. The results show that small metal Ni particle size and appropriate interaction between Ni and the support, which benefit from the in-situ preparation method are key factors that ensure the high furfuryl alcohol conversion (99.8%) and high selectivity to tetrahydrofurfuryl alcohol (98.2%) at moderate reaction conditions (120 °C, 30 min, 4 MPa H 2 ). Graphical Abstract
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Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 10
·9045-9056
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IF 4.987
Liu Peng,Xu Junming,Li Jing,Zhou Minghao,Shang Shibin,Zhao Jiaping,Jiang Jianchun
Triglycerides is a kind of natural oil widely existing in animals and plants, and it is also an ideal raw material for preparing biomass liquid fuel. Selectively hydrotreatment of unsaturated glyceride is an important strategy for the production of fuels and chemical feedstocks. In this work, catalytic hydrotreatment of triglycerides over Ni-based catalysts was investigated. Thus, an array of metal–organic frameworks derived Ni@C catalysts synthesized under different temperatures (350 °C, 400 °C, 450 °C) were prepared and applied for hydrotreatment of triglycerides. The highest conversion of triglycerides was 98.9% and the cracking rate could achieve 4.61% over the optimal Ni@C-BTC-400 catalyst in cyclohexane at 320 °C. The physicochemical characterizations were carried out by means of powder X-ray diffraction, scanning electronic microscopy, thermo gravimetric analyzer, N 2 adsorption–desorption, and Raman. Based on the optimal reaction condition (320 °C, 3 h, 3.0 MPa H 2 ), five typical vegetable oils and gutter oils were selected for the hydrotreatment study to investigate the adaptability of Ni@C-BTC-400 catalyst. The result indicated that Ni@C-BTC-400 catalyst performed good universality, and could transform oil raw materials with different fatty acid carbon chain structure to desired alkanes. Furthermore, the optimal Ni@C-BTC-400 catalyst could be carried out in next two consecutive recycling runs and could also be regenerated by H 2 for the following experiments.
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CHEMISTRY-A EUROPEAN JOURNAL
·
2021
·Vol. 27
·期 35
·9031-9037
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IF 5.236
Yibo Zhang,Yuying Zheng,Hongbo Geng,Yang Yang,Minghui Ye,Yufei Zhang,Cheng Chao Li
Graphical Novel structured M 2 P 2 O 7 /C (M=Fe, Co, Ni) nanoflake composites are prepared via an organic-phosphors precursor assisted solvothermal method and a post high temperature annealing process, which could deliver superior potassium storage performance. Metal phosphates have been widely explored in lithium ion batteries and sodium ion batteries owing to high theoretical capacities, mild toxicity and low cost. However, their potassium ion battery applications are less reported due to the limited conductivity and the slow diffusion kinetics. Considering these drawbacks, novel structured M 2 P 2 O 7 /C (M=Fe, Co, Ni) nanoflake composites are prepared through an organic-phosphors precursor-assisted solvothermal method and a subsequent high temperature annealing process. The designed Co 2 P 2 O 7 /C composite exhibits the highest rate capacity with 502 mAh g −1 at 0.1 A g −1 and good cyclability for 900 cycles at 1 A g −1 and 2 A g −1 when compared with Ni and Fe based composites. The superior electrochemical performance can be attributed to their unique nanoparticle-assembled nanoflake structure, which can afford enough active sites for K + intercalation. In addition, the robust pyrophosphate crystal structure and the in situ formed carbon composition also have positive effects on enhancing the long-term cycling performance and the electrode's conductivity. Finally, this organic-phosphors precursor induced simple approach can be applied for easy fabrication of other pyrophosphate/carbon hybrids as advanced electrodes.
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PubMed
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Caihong Xue,Dandan Jin,Hui Nan,Haomin Wei,Huiyuan Chen,Chao Zhang,Shiai Xu
Poly(vinylidene fluoride) (PVDF) gel polymer electrolytes (GPEs) show great potential for application in lithium-ion batteries (LIBs) due to their outstanding characteristics. However, the inferior thermal stability and low ionic conductivity limit their practical application. Herein, γ-LiAlO2 was synthesized and applied in a polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP)-polybenzimidazole containing an ether bond (OPBI)-polyoxyethylene (PEO) (PHOP-LAO) GPE for improving its thermal stability and ionic conductivity properties. The ionic conductivity of PHOP-LAO is 4.83 mS cm–1, which increased by 210% compared with that of the PHOP sample. It is worth noting that the thermal shrinkage of the PHOP-LAO membrane is greatly reduced (less than 1% at 230 °C for 1 h). PHOP-LAO shows outstanding thermal stability, which is beneficial for the safety of LIBs. When the PHOP-LAO GPE was applied to LIBs with Li1.04Ni1/3Co1/3Mn1/3O2 as a cathode, the LIBs exhibit remarkable and stable cycling performance with a discharge capacity retention rate of 85% after 500 cycles at a 2 C rate and maintain a power capability retention rate of up to 77% of the initial capability at the high rate of 10 C (50 °C). PHOP-LAO thus shows great potential for achieving ultra-stable and safe LIBs in the future.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2021
·
IF 6.291
Jinsong Zhang,Jie Cui,Xinying Li,Xiaohui Hao,Lingli Guo,Hongli Wang,Heliang Liu
Silicosis, a type of lung inflammation and fibrosis caused by long-term inhalation of SiO 2 particles, lacks effective treatment currently. Based on the results of our previous animal experiments, in lungs of SiO 2 -induced silicosis rats, a large number of lymphatic vessels are generated in the early stage of inflammation, which is of great significance for the removal of dust and inflammatory mediators. Here, the molecular mechanism of lymphangiogenesis is further studied. Vascular endothelial growth factor (VEGF-C) is a key pro-lymphangiogenic factor, and its elevated expression is closely related to lymphangiogenesis. In this investigation, we demonstrated that the protein level of VEGF-C was differentially expressed in bronchoalveolar lavage fluid (BALF) and alveolar macrophages (AM) in silicosis patients and healthy controls. We further stimulated human monocyte-macrophage line U937 with SiO 2 , collected the culture supernatants as conditioned medium (CM) for culturing lymphatic endothelial cells (LECs) in vitro, and observed the expression of VEGF-C in the supernatant and its effect on LEC tube formation. The results showed that both CM and single VEGF-C recombinant protein stimulation significantly enhanced LEC proliferation [(1.80 ± 0.18), (1.73 ± 0.16)], chemotaxis [chemotactic cell number (101.40 ± 13.83), (93.40 ± 9.61)], and tube formation [tube number (32.20 ± 7.26), (25.00 ± 6.25); branch number (77.20 ± 6.80), (84.60 ± 7.90)], whereas CM treated with VEGF-CmAb inhibited the proliferation (1.37 ± 0.17), chemotaxis [chemotactic cell number (57.40 ± 8.62)], and tube formation [tube number (7.40 ± 1.85); branch number (47.20 ± 13.44)] of LECs. In addition, CM and VEGF-C can promote the expression of vascular endothelial growth factor receptor 3 (VEGFR-3) and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) in LECs, which may further mediate lymphangiogenesis by up-regulating the Src/eNOS downstream signaling molecular pathway. This study is the first to clarify the molecular mechanism of pulmonary lymphangiogenesis in silicosis and may point in the direction of eventual treatments, surveillance, and regulation at a molecular level.
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PubMed
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Daxue Du,Yulian Zeng,Chenbo Wang,Mingjie Li,Fengyan Wang,Zhaopeng Xu,Haiyan Wang
Monodisperse silica nanospheres with different diameters between 100 and 700 nm were fabricated using a slightly modified Stöber process. Silica nanosphere monolayers in a hexagonal array based on hydrophobically modification were well deposited on top of a bare crystalline silicon solar cell by a Langmuir-Blodgett method. The antireflection effect of various diameter silica nanospheres coatings was simulated using Comsol Multiphysics simulations. Silica nanosphere hexagonal array coatings with four kinds of diameters were fabricated based on results of simulations. The efficiency of solar cells covered by silica nanospheres has improved significantly with a maximum of 11.41% at 119 nm diameter while that of the planar solar cells was 10.17%, which is attributed to the improved photocurrents arising from the broadband antireflection and optical absorption . The antireflection effects produced by Rayleigh (<1/10 wavelength) and Mie scattering (subwavelength) of different diameters silica nanosphere structures were discussed in detail.
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ACS Catalysis
·
2021
·
IF 13.084
Lipeng Wu,Bin Li,Yang Li,Xiaobin Fan,Fengbao Zhang,Guoliang Zhang,Qing Xia,Wenchao Peng
Herein, a series of Co@N–C materials are synthesized using nitrates (LiNO3, NaNO3, and KNO3) as templates to control the preferential growth of the cobalt (200) facet. Co@N–C–X (X = LiNO3, NaNO3, and KNO3) exhibit excellent activities and long-term stabilities for Fenton-like degradation of bisphenol A (BPA) with peroxymonosulfate (PMS) as an oxidant. The texture coefficient (TC) is used to investigate the relationship between the Co facets and their catalytic activities, and a linear relation is built between the TC of Co(200) and the reaction rate constant (k). Co(200) is therefore the most active facet for PMS activation, while nitrates can promote the preferential growth of the Co(200) facet. Moreover, the Co(200) facet is more stable against leaching and can achieve more quick transformation between Co2+/Co3+. Quenching tests, electron paramagnetic resonance spectra, and electrochemical tests show that singlet oxygen (1O2) plays the dominant role for BPA degradation. Density functional theory verifies that Co nanoparticles coated with a graphitic nitrogen-doped carbon layer have the best activity for PMS activation. This work first proposes the strategy of using nitrates to control the preferential growth of Co facets and reveals the relationship between the TC value and k, thus attracting great interest in the environmental field.
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APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jingyou Yuan,Manoj Pudukudy,Tianding Hu,Yi Liu,Xiaofei Luo,Yunfei Zhi,Hongying Su,Lihong Jiang,Shaoyun Shan
The overuse of antibiotics triggered a serious environmental crisis, stimulating the development of feasible technologies for removing antibiotics from wastewater. Herein, a set of CeO x @C-TiO 2 composites with varying amounts of CeO x from 1% to 15% were synthesized and applied for the photodegradation of tetracycline (TC) for the first time. It was found that the composites exhibited excellent performance for TC removal by degradation and mineralization under visible-light irradiation. The uniform distribution of CeO x nanoparticles in C-TiO 2 permitted the surface contact of particles, enhancing their visible light absorption with a reduced band gap of 2.39 eV and electron-transfer efficiency through the formation of heterojunctions. The amount of CeO x played a predominant role in the photocatalytic properties. The 10% composite exhibited high removal rates of 99.1%, 98.2%, and 83.5% for 10, 20, and 40 mg/L TC, respectively. Characterization experiments proved that Ce mainly existed in its +3 and +4 valence states in the composites. The interchange of these two valence states accelerated the transfer of electrons and promoted the production of superoxide anion radicals and hydroxyl radicals responsible for TC degradation. These findings provide valuable guidelines for exploiting high-performance MOF-derived photocatalysts for the abatement of contaminants.
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ChemElectroChem
·
2021
·Vol. 8
·期 18
·3512-3518
·
IF 4.59
Hong-Ji Li,Jing-Jing Li,Zhe Chen,Zhen-Zhen Wang,Jin Qu,Yi-Qian Chen,Li-Jun Zhu,Fei Jiang
Graphical Blocky road : Sodium dual-ion batteries (SDIBs) with Sb/C/G anode and expanded graphite (EG) as cathode, NaClO 4 as salts can deliver superior electrochemical performance, for example, a high discharge capacity of 376 mA h g −1 with a higher ICE (69.1 %) at current density of 500 mA g −1 , a excellent cycling stability (73 mA h g −1 is retained even after 1400 cycles at current density of 1000 mA g −1 ), and high stable CE of 99.0 %. Sodium ion-based dual ion batteries (SDIBs) have attracted increasing attentions for their high operative voltages and low cost, but their poor long-term cycling stability and rate capability largely hinder their practical applications. Here, an optimized anode-antimony/carbon/graphene (Sb/C/G) composite for SDIBs is designed. Sb nanoparticles (NPs) not only can enhance the specific capacity but also facilitate the Na + diffusion kinetics. The continuous conductive carbon matrix can promote the electron transfer process and accommodate volume changes of Sb NPs during sodiation/desodiation. Therefore, superior electrochemical performance, for example, a high discharge capacity of 376 mA h g −1 with a higher ICE (69.1 %) at current density of 500 mA g −1 , an excellent cycling stability (73 mA h g −1 is retained even after 1400 cycles at current density of 1000 mA g −1 ), and high stable CE of 99.0 %. Our study offers a suitable design for Na + -based batteries anode structure and accelerates their practical applications.
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Energies
·
2021
·Vol. 14
·期 15
·4520
·
IF 3.004
Xiaokang Yang,Jiaqi Sun,Guang Jiang,Shucheng Sun,Zhigang Shao,Hongmei Yu,Fangwei Duan,Yingxuan Yang
Membrane water content is of vital importance to the freezing durability of proton exchange membrane fuel cells (PEMFCs). Excessive water freezing could cause irreversible degradation to the cell components and deteriorate the cell performance and lifetime. However, there are few studies on the critical membrane water content, a threshold beyond which freezing damage occurs, for cold storage of PEMFCs. In this work, we first proposed a method for measuring membrane water content using membrane resistance extracted from measured high frequency resistance (HFR) based on the finding that the non-membrane resistance part of the measured HFR is constant within the range of membrane water content of 2.98 to 14.0. Then, freeze/thaw cycles were performed from −50 °C to 30 °C with well controlled membrane water content. After 30 cycles, cells with a membrane water content of 8.2 and 7.7 exhibited no performance degradation, while those higher than 8.2 showed significant performance decay. Electrochemical tests revealed that electrochemical surface area (ECSA) reduction and charge transfer resistance increase are the main reasons for the degradation. These results indicate that the critical membrane water content for successful cold storage at −50 °C is 8.2.Keywords:freezing durability;cold start;membrane water content;performance degradation;proton exchange membrane fuel cell
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Journal of Cleaner Production
·
2021
·
IF 9.297
Wenning Yang,Jia Li,Yangsai Lyu,Xiaohui Yan,Ping Yang,Min Zuo
Artificial self-propelled micro/nano-motors have emerged as a promising hot spot in the fields of water-body remediation and environmental protection. Herein, we report a novel multifunctional micromotors with dual enzyme-like activities for simultaneous colorimetric determination and removal of environmental contaminants. Thanks to the tubular morphology inherited from kapok fibers, these bovine serum albumin-functionalized NiCo 2 O 4 @MnO 2 /C (BSA-NiCo 2 O 4 @MnO 2 /C) micromotors with dual oxidase/peroxidase-like activity can move forward quickly in aqueous solutions via a bubble recoil mechanism, which can not only enhance the colorimetric sensing performance, but also improve the removal efficiency toward Cu 2+ ion by enhancing the mass transfer both in the detection and catalytic degradation systems. Moreover, the unique 3D hierarchical architecture assembled by core-shell NiCo 2 O 4 @MnO 2 nanosheets and C microtubes can provide more accessible reactive sites and thus dramatically facilitate such detection process. In combination with the autonomous motility, intrinsic oxidase/peroxidase-like activities and precisely tuned hierarchical architecture, these automatic micromachines not only are able to detect Cu 2+ selectively and sensitively with the limit of detection of 2.0 nM, but also quickly remove Cu 2+ from wastewater with maximal adsorption capacity of 161.8 mg g −1 . Furthermore, these micromotors exhibit excellent catalytic activity for the degradation of tetracycline hydrochloride. This multifunctional mobile platform will provide a new and promising strategy for the simultaneous detection and decontamination of poisonous metal ions and other pollutants in aqueous samples.
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