JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 8
·D276
·
IF 3.12
Yu-Ke Zhong,Kui Liu,Ya-Lan Liu,Yue-Xiang Lu,Tai-Qi Yin,Lin Wang,Zhi-fang Chai,Wei-Qun Shi
Uranium-molybdenum (U-Mo) alloys especially the γ-U-Mo phase, with excellent irradiation performance at high temperatures, have been extensively studied as low-enriched-uranium candidate fuels for strengthening nuclear security and nonproliferation worldwide. Herein, we provide a facile method to successfully prepare the γ-U-Mo alloys (U-10Mo and U-8Mo) directly from oxide precursors via electro-reduction by constant cell voltage electrolysis in LiCl molten salt at 986 K. The reduction mechanism was elucidated through cyclic voltammetry using the metallic cavity electrode (MCE) combined with XRD, SEM and EDS characterizations toward the electrolysis products under different conditions. It was found that the reduction of mixed MoO3-UO2 oxides may take place in three steps. Firstly, MoO3 was reduced to Li4Mo5O12, and then Li4Mo5O12 was converted into Mo. Finally, the U-Mo alloys were formed due to the underpotential deposition of U on the pre-formed Mo. In addition, the effects of cell voltage, sintering temperature and mixture composition on the electrochemical reduction were investigated. The results found that the reduction rate increased with the augmentation of applied potential and the decrease of sintering temperature. Moreover, the favorable composition of the mixed precursor varied from 24 at% to 21at%. The reduction conversion rate was determined to be 93.7% by ICP and TGA.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 21
·13036-13042
·
IF 3.269
Fenfen Lu,Yan Xu,Xia Jiang,Yang Liu,Jiale Huang,Daohua Sun
Low temperature 1,3-butadiene hydrogenation over biosynthesized Pd/γ-Al2O3 catalysts annealed under different atmospheres (H2 and air) was compared in a fixed bed reactor, and the catalysts were prepared using a facile sol-immobilization method. The structural properties of the Pd/γ-Al2O3 catalysts in relation to their activities in 1,3-butadiene hydrogenation were investigated by X-ray photoelectron spectroscopy, X-ray diffraction, hydrogen temperature-programmed reduction, thermogravimetry, transmission electron microscopy, CO chemisorption measurement techniques and Fourier transform infrared spectroscopy. The results of characterization revealed that the calcination atmosphere (H2 and air) exhibited a remarkable impact on the chemical state of Pd species and catalytic activity, and the coexistence of the metallic state and oxidation state of Pd was a key factor for higher catalytic activity and butene selectivity, while the catalyst with the existence of the metallic state only (H2–Pd/γ-Al2O3) showed lower butene selectivity, and the catalyst with the oxidation state alone (air–Pd/γ-Al2O3) hardly showed any activity in 1,3-butadiene hydrogenation. Therefore, the chemical state of Pd played an important role in the 1,3-butadiene hydrogenation reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2022
·
IF 6.562
Mingsheng Luo,Chenmeng Li,Qinglong Liu,Zhi Yang,Yatao Wang,Hongjuan Li
Direct hydrogenation of CO to alcohols through Fischer-Tropsch reaction process is taken great interest in recent years. In this study, a series of β-Mo 2 C/γ-Al 2 O 3 catalyst are prepared to investigate the influence of carbon and molybdenum precursor, calcination temperature, as well as the molar ratio of the carbon precursor to molybdenum precursor compounds on catalyst microstructures and the catalytic performance. The microstructure characteristics of the catalysts were examined with XRD, BET, ICP, SEM and CO-TPD. The performance test of the catalysts for syngas-to-alcohol was investigated in a fixed-bed reactor. Properly excessive amount of hexamethylenetetramine as carbon precursor calcined at a high temperature (≥700 ℃) favors the formation of high crystalline β-Mo 2 C on γ-Al 2 O 3 carrier. Catalysts with different amount of Mo were prepared to study the effect of active metal loading on microstructure and catalytic performance. The results show that the particle size of β-Mo 2 C and CO dissociation adsorption capacity, as well as the CO conversion increases with raised Mo loading. The selectivity of all higher alcohols reached the maximum when 25 % of Mo was loaded.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 94
·期 1
·167-177
·
IF 2.587
Xuejuan Cao,Junnan Wei,Huai Liu,Xinyue Lv,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Shijie Liu,Lu Lin
BACKGROUND γ-Valerolactone (GVL) is a versatile biomass-derived platform molecule that could serve as a building block to produce chemicals, materials and fuels, but the production of GVL from biomass via a cost-competitive method is challenging. In this contribution, a robust Cu─Mg oxide was prepared as an efficient bifunctional catalyst for both H 2 production by MeOH reforming and hydrogenation of methyl levulinate (ML) to GVL in MeOH medium. RESULTS Cu 0.87 Mg 0.13 O x prepared by a urea hydrolysis method offered a GVL yield up to 90.6% at 220°C in 4 h without external hydrogen. This catalyst could be reused for at least seven consecutive cycles without loss of its activity. Notably, Cu 0.87 Mg 0.13 O x also provided nearly 70% GVL yield in methanolysis products of cellulose in the presence of humins. Characterization of the catalyst indicates that the incorporation of MgO greatly facilitates the stabilization of Cu + species that possess a better catalytic performance in ML hydrogenation compared with metallic Cu. CONCLUSION This robust Cu 0.87 Mg 0.13 O x could greatly contribute to develop a highly facile and desirable two-step strategy for GVL production from cellulose, through the integration of ML production by methanolysis of cellulose, H 2 formation by MeOH reforming and ML hydrogenation in MeOH medium. © 2018 Society of Chemical Industry
研究领域:
化学工程
·
可再生资源化学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2017
·Vol. 228
·期 9
·1-6
·
IF 1.702
Fei Xionghui,Ling Yongsheng,Shan Qing,Hei Daqian,Jia Wenbao
Hexavalent chromium is a type of toxic chemical, it may cause allergies, hereditary genetic defects and cancer in humans by inhalation, and it is also a persistent danger to the environment. However, chromium metal, trivalent chromium and tetravalent chromium have low toxicities. In this study, semiconductor materials (quartz fibre and TiO 2 ) were added to a hexavalent chromium solution and the removal efficiency of hexavalent chromium as a function of the γ-ray irradiation dose, as well as the catalytic mechanism, was investigated. It was observed that the reduction of hexavalent chromium by γ-ray irradiation was largely promoted in the presence of semiconductor materials; the semiconductor materials act as catalysts under the gamma-ray irradiation. The hexavalent chromium in the solution can be converted to an insoluble precipitate by gamma-ray irradiation. These results are highly beneficial to apply semiconductor materials as catalysts for the removal of contaminants by radiation.
研究领域:
环境科学
·
辐射化学
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2017
·
IF 3.151
Min Zhang,Junhui Yang,Cuicui Ding,Liulian Huang,Lihui Chen
Native collagen cannot be dissolved in neutral pH buffer, limiting its application in many fields. The traditional method to prepare water-soluble collagen is succinylation modification, which causes the decrease in the thermal stability. Therefore, poly(γ-glutamic acid)- N -hydroxysuccinimide (γ-PGA-NHS) esters were used as a novel modifying agent of collagen. FTIR results indicated the intact retention of native triple-helix structure after modification. Isoelectric point of the modified collagens shifted continuously to lower values with increasing the γ-PGA-NHS/collagen ratios (w/w). Consequently, the modified collagen can form a clear solution in neutral pH buffer. Furthermore, the denaturation temperature (T d ) of the modified collagens reached 44.8–49.9 °C, which were 6.0–11.1 °C higher than that of native collagen. However, it should be noted that gelation occurred when modifier/collagen ratio (w/w) = 50% as γ-PGA-NHS with a relatively high esterification degree was used. As a whole, these results indicated that dual-functional modification in regards to both of water solubility and thermal stability on collagen can be achieved using γ-PGA-NHS esters with a relatively low esterification degree. In addition, the proliferation of fibroblasts could be promoted as reflected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and 4′,6-diamidino-2-phenylindole (DAPI) method, suggesting the excellent cytocompatibility of the modified collagens. The present study provided useful information to the design of novel water-soluble collagen, which could be applied in the fields including biomaterials, cosmetics etc.
研究领域:
生物材料
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Wenxiu Yang,Zhiqing Ge,Guoqing Xu,Chu Zhao,Mozhen Wang,Shengchi Zhuo,Xuewu Ge
The synthesis and stable loading of metal nanoclusters have always been a hot and difficult topic in the field of nano-metal catalysts. In this work, micron-sized inverse opal SiO 2 microspheres (IO-SiO 2 ) are firstly prepared as the carrier of platinum nanoclusters (PtNCs) through a sol-gel process of tetraethyl orthosilicate (TEOS) on sacrificed polystyrene (PS) colloidal crystal microspheres template. After the IO-SiO 2 carriers are dispersed into the aqueous solution of H 2 PtCl 6 and irradiated by 60 Co γ-ray radiation for a certain absorbed dose in a deoxygenized atmosphere, PtNCs with a size of less than 2 nm are in situ synthesized based on a redox equilibrium of Pt(0)/Pt(IV) induced by effect of the reductive species (e aq − , H ) and oxidizing radicals (HO ) produced by the radiolysis of water, and immobilized on IO-SiO 2 without the help of any stabilizer. Due to the large pore volume of the IO-SiO 2 , the loading capacity of PtNCs can reach as high as 18.63 μg/mg microsphere . The prepared IO-SiO 2 -supported PtNCs (PtNCs@IO-SiO 2 ) show excellent catalytic activity and recyclability for the reduction of o-nitroaniline by NaBH 4 as the model reaction. This work offers a new route to prepare stable and high-performance metal nanocluster catalysts loaded on porous microspheres using γ-ray radiation technique.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 131
·期 21
·
IF 1.64
Yan Wu,Yong Deng,Qiulin Yuan,Ying Ling,Haoyu Tang
A series of thermoresponsive poly(γ-propyl- L -glutamate)-graft-(oligo ethylene glycol)s (PPLG-g-OEGs) with different main-chain and side-chain lengths have been synthesized via copper-mediated alkyne-azide 1,3-dipolar cycloaddition between poly(γ-azidopropyl- L -glutamate)s (PAPLG) and propargyl terminated oligo ethylene glycols (Pr-OEGs). Fourier transform infrared spectrometer analysis revealed that PAPLG 10 adopted 39.4% β-sheet, 47.4% α-helix, and 13.2% random coil while PAPLG with longer main-chain length (DP = 37 and 88) and PPLG-g-OEGs adopted exclusive α-helix in the solid state. Circular dichroism analysis revealed that PPLG-g-OEGs adopted α-helical conformations with helicities in the range of 50∼100%. The thermoresponsive behaviors of PPLG-g-OEGs in water have been studied by dynamic light scattering. The polymer concentration, main-/side-chain length, and helicity collectively affected their cloud point temperatures. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 41022.
研究领域:
高分子化学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Yang Peng,Haikuan Yang,Ting Zhang,Songsong Zhou,Haiwei Jiang,Yongjie Zheng,Weiran Yang
Synthesis of γ -butyrolactone (GBL) from renewable biomass resources under mild reaction condition with catalysis is attractive but challenging. Herein, we report the photocatalytic oxidation of the biomass-based furfural derivative tetrahydrofurfuryl alcohol (THFAL) to prepare GBL under light irradiation (365 nm) in air at room temperature. Utilising Ru/TiO 2 as the photocatalyst and air as the oxidant, a GBL yield as high as 73 % was achieved. The reaction mechanism was studied rigorously by performing photocatalyst performance evaluation, material characterisation, free-radical quenching reactions and electron spin resonance (ESR). In situ diffuse reflectance infrared Fourier transform spectroscopy was employed to detect intermediate products and elucidate the mechanism at the molecular level. Based on the in-situ monitoring results, we propose a pathway for the oxidation decarbonylation of THFAL to produce CO 2 and GBL.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Fukun Li,Zhangmin Li,Liam John France,Jiali Mu,Changhua Song,Yuan Chen,Lilong Jiang,Jinxing Long,Xuehui Li
Novel and selective strategies for platform chemical production from renewable biomass are highly attractive in respect to value-added utilization of sustainable resources. In this study, a series of low-cost, commercially available, transition metal carbonates (Zr, Ni, Mg, Zn, and Pb) were investigated for catalytic transfer hydrogenation of levulinate esters to γ-valerolactone (GVL) via the cascade process of Meerwein–Ponndorf–-Verley (MPV) reduction and lactonization reaction. Among the selected catalysts, basic zirconium carbonate is the most active, with the highest turnover frequency (TOF) of 3.1 h–1 and a surface reaction rate of 0.21 mol m–2 h–1. At 453 K, 3.0 h, and 1.0 MPa N2, 100% ethyl levulinate conversion, 96.3% GVL yield, and 91.9% hydrogen donor utilization are observed due to the cooperative effect between acid (Mn+) and base (−OH) sites. Furthermore, this catalyst shows high recyclability under the optimized conditions, where a satisfactory catalytic activity is shown even after six consecutive runs.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Xiaolin Bi,Nan Zhao,Meina Guo,Weihua Zhang,Fengping Zhou,Wuming Xie,Ruigang Wang
Roxarsone (ROX), a livestock growth enhancer, poses environmental and health hazards due to its remarkable stability, making traditional degradation methods ineffective. To tackle this issue, a novel Fenton-like composite, composed of nanoscale zero-valent iron supported on γ-aluminum oxide (nZVI/γ-Al 2 O 3 ), was synthesized to boost ROX degradation. Results demonstrated nearly complete mineralization of the ROX organic matrix within just 180 min, facilitated by the Lewis acidity sites of γ-Al 2 O 3 . Significantly, this composite exhibited selective adsorption of released AsO 4 3− ions on its surface, forming FeAsO 4 and Fe-As-Al complexes. It also established an internal redox cycle involving Fe(0), Fe(II), and Fe(III), ensuring a continuous and efficient generation of primary reactive oxygen species (·OH and O 2 ·− ). Thus, a simultaneous redox process occurred on the composite surface can be attributed to the synergy of the reducibility of nZVI and the oxidation catalyzed by ·OH and O 2 ·− . Initially, the nitro group of ROX was reduced by nZVI, forming more hydrophilic o-aminophenol, favoring subsequent oxidation and mineralization. Simultaneously, the As-C bonds in ROX were oxidized, yielding AsO 4 3− , which was subsequently adsorbed over extended reaction times. This innovative approach offers a potential solution for treating wastewater contaminated with metalloid-organic composite pollutants, addressing the environmental and health concerns associated with ROX residues.
研究领域:
环境科学
·
化学
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Zhongdi Liu,Rui Zhang,Huai Liu,Junhua Zhang,Yong Sun,Naya Li,Lincai Peng
Developing efficient and stable solid functional materials for the catalytic upgrading of biomass-based platform furanic molecules is of great significance to produce value-added chemicals and biofuels. We herein report β-zeolite (β)/biobased carbon hybrids supported Zr species towards the cascade conversion of furfural into γ-valerolactone (GVL) with high activity and favorable stability. The role and importance of carbon modifier were highlighted. The cellulose (CEL) modified Zr/β-CEL catalyst was found to be uniquely effective, leading to an increase of GVL yield from 49.3% to 81.1%. Catalyst characterizations revealed that the structural integrity of β was largely preserved using CEL as the carbon modifier, accompanied by the increased mesopore volume and pore size for better accessibility of active sites and diffusion of reactants. Simultaneously, the presence of CEL offered an appropriate ratio of Lewis and Brønsted acid sites due to the well incorporation and dispersion of Zr species, which ensured the successive transfer hydrogenation and ring-opening reactions. Kinetic studies demonstrated the positive effect of CEL modification on reducing the apparent activation energy and thereby facilitating the GVL formation. More importantly, Zr/β-CEL with enhanced structural stability also exhibited markedly higher recyclability compared with the pristine Zr/β. The understanding on the roles of carbon modifier can be employed to optimize the physicochemical properties of zeolite-based catalysts for roundly improving the catalytic reactivity of biomass-related compounds.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）