APPLIED CATALYSIS B-ENVIRONMENTAL
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2016
·
IF 8.328
Jing Guo,Shanhui Zhu,Youliang Cen,Zhangfeng Qin,Jianguo Wang,Weibin Fan
A series of ordered mesoporous Nb x W (8 − x) oxides with tunable Nb/W ratio were successfully synthesized by evaporation-induced self-assembly method. The mesoporous structure, morphologies, surface chemical state, and acidic properties of these catalysts were fully characterized by low-temperature sorption of N 2 , small-angle and wide-angle XRD, TEM, Raman, XPS, and Py-IR. It was shown that the Nb x W (8 − x) oxides created large amounts of Lewis as well as Brønsted acid sites, which promoted the isomerization of glucose to fructose followed its dehydration to 5-hydroxymethylfurfural (HMF). Mannose was also formed via the epimerization of glucose. Of them, the mesoporous Nb 4 W 4 exhibited the best catalytic activity with a comparatively low E a about 90.2 kJ/mol and good stability in aqueous medium. The kinetic behavior revealed that Lewis acid sites facilitated to glucose-to-fructose isomerization while Brønsted acid sites promoted the dehydration of fructose to form HMF.
研究领域:
催化化学
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生物质转化
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绿色化学
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多相催化
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材料化学
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碳水化合物化学
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DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2016
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IF 1.112
Xiaolong Wang,Yonghong Liu,Hang Dong,Qiang Sun,Yang Shen,Renjie Ji
A three-step model of the transitional phase inversion (TPI) process for the formation of water-in-oil (W/O) emulsions is presented. Three types of emulsions exist in an emulsification process at different oil–water ratios and hydrophilic–lipophilic balance (HLB). A stable W/O emulsion was obtained using Sorbitan oleate (Span 80) and polyoxyethylenesorbitan monooleate (Tween 80) with a specified HLB and oil volume fraction. Oil was added into water, which contained the water-soluble surfactant, to dissolve the oil-soluble surfactant. This route allowed TPI to occur, and an interesting emulsification process was observed by varying the HLB, which corresponded to the change in the oil–water ratio. Two types of emulsions in the emulsification process were found: transition emulsion 1 (W/O/W high internal phase emulsion) and target emulsion 2 (W/O emulsion with low viscosity). This study describes the changes that occurred in the emulsification process.
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Dan Zhang,Chenyu Li,Bin Song,Huaifang Zhang,Jin Liu,Yuyao Chen,Chong Zhang,Lei Wang,Yuanyuan Feng
We propose a strategy of W doping to synergistically modulate the electronic structure and surface chemistry of Ru. • RuW 5% /CNT achieves a bifunctional breakthrough with HER and ClER in a unified strongly acidic medium. • Electron transfer from W to Ru downshifts the d-band center, optimizing H*/Cl* adsorption while suppressing O* adsorption. Hydrogen (H 2 ) is an important chemical in various chemical manufacturing industries. A promising method for the simultaneous production of H 2 and Cl 2 is the coupling of the cathodic hydrogen evolution reaction (HER) with the anodic chlorine evolution reaction (ClER) in an electrolyser using bifunctional electrocatalysts. In this study, a bifunctional catalyst (RuW 5% /CNT, W: 5 wt%) was designed. The catalyst was able to achieve a current density of 10 mA cm −2 in acidic HER with an overpotential of only 27 mV and a small Tafel slope with 21.5 mV dec −1 . Secondly, it was also electrochemically tested in ClER. The data showed that the overpotential of RuW 5% /CNT was 78.8 mV at a current density of 10 mA cm −2 , which was superior to that of the dimensionally stable anode (DSA). In addition, the cell voltage of RuW 5% /CNT||RuW 5% /CNT electrolyzer was only 1.626 V at a current density of 1 A cm −2 under HER and ClER coupling conditions, which provided an effective method for generating valuable chemicals. Theory calculations attribute this superior performance to the electronic modulation of Ru by W, which fine-tunes the adsorption strength of key reaction intermediates, offering a mechanistic foundation for the observed bifunctionality.
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DOI
高影响因子
ChemCatChem
·
2025
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IF 3.9
Yong Jiang,Zhenhai Zhu,Xiaoxiao Shan,Chunli Jiang,Sanzhao Song
The exsolution of nanoparticles from perovskite oxides has attracted considerable attention for oxygen evolution reaction (OER) applications owing to their exceptional stability and catalytic activity. Understanding and controlling the surface exsolution behavior of nanoparticles is critical for tuning the catalytic activity and stability of perovskite oxide. Herein, we investigate the effect of high-valence tungsten (W) doping on the exsolution behavior and OER performance of LaCo 0.8 Fe 0.15 W 0.05 O 3-δ perovskite. Compared with the pristine perovskite, W doping elevates the exsolution temperature from 600 to 650 °C, indicating a significant influence on both thermodynamics and kinetics processes. The reduced electrocatalyst exhibits remarkable OER performance, achieving an overpotential of 234 mV at 10 mA cm −2 in 1.0 M KOH, along with low Tafel slope (67 mV dec −1 ), small charge transfer resistance (20 Ω) and long-term stability, underscoring its superior charge transfer kinetics and electrical conductivity. This work provides valuable insights into the role of high-valence dopants in modulating exsolution behavior, offering guidance for the rational design of highly efficient for energy conversion applications. Graphical High-valence W doping in LaCo 0.8 Fe 0.15 W 0.05 O 3-δ increases the exsolution temperature from 600 to 650 °C and significantly enhances oxygen evolution reaction performance, achieving an overpotential of 234 mV at 10 mA·cm −2 , a Tafel slope of 67 mV·dec −1 , and a charge transfer resistance of 20 Ω, providing critical insights for designing new electrocatalysts.
研究领域:
材料科学
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电化学
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能量转换
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催化
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产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
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2023
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IF 4.7
Weiqiang Hu,Lianfeng Wei,Jun He,Songhua Chen,Shaocun Liu,Zongqing Ma,Yongchang Liu
In this work, we creatively introduced MAX additives (Ti 2 AlC) into W alloy system to break the development bottleneck of ball milling technology: a large amount of oxygen impurities and large-sized second phase particles at grain boundaries (GBs). Unlike traditional oxides/carbides, Ti 2 AlC can undergo self-decomposition during high-temperature sintering stage (>1400 °C) on the basis of hydrogen sintering, and continue to adsorb a number of stubborn oxygen impurities to form various smaller, more dispersed, and stronger in-situ Ti x C y , TiO x , Al 2 O 3 , and Al x Ti y O z nanoparticles . Furthermore, these in-situ nanoparticles could maintain stable coherent interfaces with W, thereby more effectively refining, purifying, and strengthening matrix. Compared to traditional W-carbide/oxide alloys, MAX additives render our alloy with high hardness (521 ± 24 HV 0.2 ), a remarkable combination of high compressive strength (1262.9 ± 35.1 MPa) and large ductility (9.88%). This work provides a new perspective for the preparation of high-performance refractory metals and relevant engineering application.
研究领域:
材料科学
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金属材料
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纳米材料
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粉末冶金
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结构合金
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
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2023
·Vol. 20
·期 4
·2229-2238
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IF 2.1
Zhonghuai Yi,Yi Sun,Ning Zhang,Huiwen Xiong
The miniaturization and mobility of nuclear reactors have become an important trend in the development of nuclear energy. In order to simplify the design of shielding materials with improved complexity and reduced weight, 3D B 4 C-W-based composites were fabricated via fused deposition molding using highly-filled granular feedstocks containing 62 vol% B 4 C-W powders (boron carbide accounted for 30 wt% and tungsten for 70 wt%) and 38 vol% polymer binders (60 wt% Carnauba wax, 22 wt% polypropylene, 13 wt% polystyrene, and 5 wt% stearic acid). The rheological properties and microstructure of the feedstock and extruded filaments were clarified. Roles of the printing parameters including extrusion temperature, platform temperature and deposited-layer height in the morphology of 3D composites were investigated in detail. Extruded filaments with good shape retention, dense fracture surface, and uniformly dispersed B 4 C-W grains were achieved, benefiting from the smooth printing and shear thinning behaviour of the feedstock. Defects including warping, small pores or stacking pores could be formed under improper printing parameters, owing to the poor bonding strength between deposited layers induced by thermal internal stress or decomposition of wax. 3D composites with large size of 130 × 130 × 5 mm were fabricated, which showed a satisfactory compressive strength of 34.8 MPa. This work showed a facile route to fabricate 3D radiation shielding materials based on highly-filled polymers.
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产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
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2023
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IF 4.9
Xiaopeng Hu,Anlin Zhang,Yufeng Du,Li Zhou,Changlin Li,Jingjing Lian,Zhequan Zou,Xuan Ouyang,Bin Deng,Lianwu Xie,Ruijin Yu
A novel layered perovskite tantalate phosphor Sr 3 LaTa 3 O 12 :Sm 3+ (SLTO:Sm 3+ ) with orange-red emission was obtained for the first time via the solid-phase synthetic method. The phase purity, surface morphology , element distribution and luminescent properties of the SLTO: x Sm 3+ ( x = 0.01 mol%–0.30 mol%) phosphors were investigated. Under 408 nm excitation, the optimum doped SLTO:0.10Sm 3+ phosphor emits orange-red light at 598 nm with the highest emission peak ( 4 G 5/2 → 6 H 7/2 ). The critical energy transfer distance is 1.687 nm. The prepared SLTO:0.10Sm 3+ phosphor has excellent thermal stability with temperature quenching temperature ( T 0.5 > 500 K) and high activation energy ( E a = 0.25 eV). Through calculation, the chromaticity coordinates of all samples are concentrated in the orange-red area, and the color purity reaches 99%. The fabricated white light-emitting diode (w-LED) has a good correlated color temperature (5132 K), a high R a (89), and the CIE chromaticity coordinates (0.340, 0.327). Consequently, the superiority of orange-red-emitting tantalate SLTO:Sm 3+ phosphors for w-LEDs is demonstrated.
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
·
IF 5.2
Hui Liu,Hongyan Li,Bin Lu,Songnan Li,Jingxiang Zhao,Qinghai Cai
A composite catalyst was prepared by impregnation of ZSM-5 in mixture solution of Co(NO 3 ) 2 , ZrOCl 2 and phosphotungstic acid (PW) and characterized by XRD , FT-IR, UV–vis, XPS , SEM and TEM techniques to confirm its structure and composition . The pre-prepared composite is composed of Co 2 (PO 4 )Cl, ZrO 2 , P 2 O 5 and WO 3 crystalline nanoparticles uniformly dispersed on ZSM-5 zeolite . The prepared composite demonstrates effective catalytic function for solvent-free oxidation of toluene into benzaldehyde with H 2 O 2 oxidant, achieving 16.6% conversion and 90% selectivity . The effect of various components composed of the catalyst and reaction conditions on the catalytic function were explored. Moreover, the recovery and reusability of the catalyst were estimated, presenting good reusability.
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2023
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IF 6.4
T. Zhang,H.W. Deng,Z.M. Xie,Y.W. Zhuang,S.Y. Peng,G. Hu,H. Lin
Improvement of the stability of nanocrystalline (NC) materials is always a challenge. In this paper, the high thermal stability is achieved in a representative NC W alloy by combining nano-segregation of Ti solute to W grain boundary (GBs), and in-situ formation of nano Ti–Zr–O particles, which provide both thermodynamic and kinetic stabilization effects through solute dragging and particle pinning. The recrystallization temperature of this bulk NC W alloy reaches up to 1600 °C, and these nanometric microstructures maintain stable under a long-time and high-temperature ordeal up to 1200 °C for 120 h. And its microhardness and micro-compressive yield strength are ∼17.0 and 5.14 GPa, respectively. In addition, this bulk NC W alloy has high irradiation stability due to the high densities of stabled GBs and phase boundaries. This work demonstrates the possibility of attaining high-stability bulk NC materials in terms of segregation of solutes at GBs and in-situ formation of ultrafine nanoparticles with a coherent interface with the W matrix.
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yuanxing Ning,Minghui Yao,Yuxing Li,Guangchun Song,Zhiming Liu,Qingping Li,Haiyuan Yao,Wuchang Wang
During the production and transportation of deep-water oil and gas, the low-temperature and high-pressure operating environment might induce hydrate formation and eventual blockage, which poses a serious threat to the flow assurance. Furthermore, the formation, aggregation and deposition characteristics of hydrate would become more complicated in the presence of asphaltene. Consequently, clarifying the effect of asphaltene on hydrate nucleation and growing process plays an important role in the safety production and flow assurance of deep-water oil and gas field. The kinetic characterizations of hydrate nucleation and growth in W/O systems containing asphaltene were investigated via experimental research, molecular dynamics simulations and mathematical modeling. Results revealed that the hydrate nucleation induction time increased with the increase of asphaltene content. The inhibition of hydrate nucleation by asphaltene in high-pressure (5 MPa) experiments was more pronounced than that in low-pressure (3 MPa). On the other hand, asphaltene restrained hydrate formation and the total gas consumption decreased with the increase of asphaltene content. The dynamic adsorption process of asphaltene at oil–water interface and the evolution of the surface coverage with time were elucidated by jointly solving the Ward-Tordai and Langmuir equation. Combined with the above aspects, the induction time model containing asphaltene was developed, which could provide a new perspective and methodology for deep-water flow assurance
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Run Zheng,Baolong Wang,Kai Shi,Di Sha,Xiangling Ji
The emulsion separation of oily wastewater is always a challenge topic in both fundamental research and practical application. In this paper, polyvinyl alcohol formaldehyde composite sponges (PVF/PVF) with hierarchical pore structure were established by physical absorption/chemical crosslinking and hydrophobic modification via introducing hydrophobic long alkyl chain. As a result, pore size was adjusted from 74.8 µm of pristine PVF to less than 20 µm of hydrophobic PVF, the water contact angle was 120° for final as-prepared sponges, i.e. size sieving and surface wettability could meet the need of emulsion separation. As-prepared sponges could separate W/O (water-in-oil) emulsion efficiently only under the action of gravity, with a maximum flux of 2.9 × 10 5 L m -2 h −1 bar −1 and separation efficiency nearly 100 %. More importantly, the as-prepared sponges displayed excellent reusability, which could be recovered by simply washing. These composite sponges, which were obtained by a simple method and low cost, could be easily scaled up in practical production process, providing an outstanding candidate material for efficient W/O emulsion separation.
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产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Yan Jiabiao,Xia Mingkun,Zhu Chenguang,Chen Dawei,Du Fanglin
Perovskite oxides have been established as a promising kind of catalyst for alkaline oxygen evolution reactions (OER), because of their regulated non-precious metal components. However, the surface lattice is amorphous during the reaction, which gradually decreases the intrinsic activity and stability of catalysts. Herein, the precisely control tungsten atoms substituted perovskite oxides (Pr0.5Ba0.5Co1-xWxO3-δ) nanowires were developed by electrostatic spinning. The activity and Tafel slope were both dependent on the W content in a volcano-like fashion, and the optimized Pr0.5Ba0.5Co0.8W0.2O3-δ exhibits both excellent activity and superior stability compared with other reported perovskite oxides. Due to the outermost vacant orbitals of W6+, the electronic structure of cobalt sites could be efficiently optimized. Meanwhile, the stronger W-O bond could also significantly improve the stability of latticed oxide atoms to impede the generation of surface amorphous layers, which shows good application value in alkaline water splitting.
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产品关联
DOI
PubMed
高影响因子
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