JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 25
·9095-9102
·
IF 5.101
Xinyong Tao,Yiping Li,Jun Du,Yang Xia,Yingchao Yang,Hui Huang,Yongping Gan,Wenkui Zhang,Xiaodong Li
Finding a general procedure to produce a whole class of materials in a similar way is a desired goal of materials chemistry. In this work, we report a new bamboo-based carbothermal method to prepare nanowires of covalent carbides (SiC and B4C) and interstitial carbides (TiC, TaC, NbC, TixNb1−xC, and TaxNb1−xC). The use of natural nanoporous bamboo as both the renewable carbon source and the template for the formation of catalyst particles greatly simplifies the synthesis process. Based on the structural, morphological and elemental analysis, volatile oxides or halides assisted vapour–liquid–solid growth mechanism was proposed. This bamboo based carbothermal method can be generalized to other carbide systems, providing a general, one-pot, convenient, low-cost, nontoxic, mass production, and innovative strategy for the synthesis of carbide nanostructures.
研究领域:
材料化学
·
纳米材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Changjiang Liu,Hu Zang,Xin Liu,Haiyan Lu,Nan Yu,Baoyou Geng
Copper-based catalysts demonstrate distinctive multicarbon product activity in the CO2 electroreduction reaction (CO2RR); however, their low selectivity presents significant challenges for practical applications. Herein, we have developed a multilevel porous spherical Cu2O structure, wherein the mesopores are enriched with catalytic active sites and effectively stabilize Cu+, while the macropores facilitate the formation of a “gas–liquid–solid” three-phase interface, thereby creating a microenvironment with an increasing water concentration gradient from the interior to the exterior. Potential-driven phase engineering and protonation synergistically optimize the reaction pathway, facilitating a switch between CO and C2H4. At a low current density of 100 mA cm–2, the faradaic efficiency (FE) for CO reaches an impressive 96.97%. When the current density increases to 1000 mA cm–2, FEC2H4 attains 53.05%. Experiments and theoretical calculations indicate that at lower potentials, the pure Cu2O phase diminishes the adsorption of *CO intermediates, while weak protonation inhibits hydrogen evolution reactions, thereby promoting CO production. Conversely, at more negative potentials, the Cu0/Cu+ interface and strong protonation generate locally elevated concentrations of *CO and *COOH intermediates, which enhance C–C coupling and deep hydrogenation, ultimately improving selectivity toward C2+ products. This study provides novel insights into the rational design of copper-based catalysts for customizable CO2 electroreduction products.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Chemistry & Engineering
·
2019
·Vol. 4
·期 4
·715-723
·
IF 3.935
Hao Feng,Xun Zhu,Biao Zhang,Rong Chen,Qiang Liao,Dingding Ye,Jian Liu,Ming Liu,Gang Chen,Kun Wang
The hydrodynamic characteristics of gas–liquid two-phase flow can significantly affect the performance of gas–liquid–solid microreactors. Using nitrobenzene hydrogenation as the reference heterogeneous catalytic reaction, the two-phase reacting flow behavior was visualized and characterized. Distinct differences in the length evolution, migration velocity and residence time of gas slugs were noticed for the reaction and non-reaction cases. The interface retraction of a gas slug was observed, which was mainly due to the hydrogen consumption at the gas pressure accumulation stage. Moreover, effects of the gas and liquid flow rates as well as the inlet nitrobenzene concentration on the two-phase flow behaviors and microreactor performance were also investigated. The results suggested that increasing the gas flow rate could enhance nitrobenzene conversion, but this effect was inhibited by the reduced residence time at high gas flow rates. Higher nitrobenzene concentration could enhance the interface retraction and extend the residence time, and together promote aniline production but in a trade-off with the conversion. This work reveals the intrinsic interaction between two-phase flow behaviors and catalytic reaction in microreactors, which can play a significant role in the development of microreactor technology.
研究领域:
化学工程
·
催化反应工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zichang Yang,Yuyao Xu,Li He,Xingkai Lu,Xiaolong Yao,Changming Li,Hainan Gao,Zhiliang Yao,Chao Wu
Photocatalytic oxidation technology holds considerable promise for effectively removing odor-causing compounds, yet conventional gas–solid photocatalytic systems suffer from critical limitations, including incomplete mineralization and persistent accumulation of toxic intermediates. To address this, a gas–liquid-solid photocatalytic oxidation system was developed utilizing a superhydrophilic/superhydrophobic photocatalyst. By synthesizing superhydrophobic Cu-doped UiO-66 and combining with TiO 2 , the resulting OCUN/T photocatalysts was thoroughly chatacterized and tested under various conditions. The optimized system achieved sustained methyl mercaptan removal rates exceeding 99 % over 10 h under low flow rates. Performance significantly improved under solar irradiation irradiance > 100 W/m 2 . This work elucidates the synergistic mechanism of interfacial mass transfer and photocatalytic degradation in the gas–liquid-solid system, providing a method for the purification of odor-causing compounds that minimizes secondary pollution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Energy
·
2021
·
IF 7.311
Pu Wang,Jiaqi Zhao,Run Shi,Xuerui Zhang,Xiangdong Guo,Qing Dai,Tierui Zhang
As a promising environmental treatment technology, photocatalysis has been investigated for decades and even tentatively practiced in actual large-scale applications. However, most researches focus on photocatalytic kinetics (excitation, charge transfer, and surface reaction) but ignore the significant impact of oxygen interfacial mass transfer for photocatalytic aerobic oxidation in aqueous media. Here, we use finite element simulation to demonstrate that during photocatalysis, the remained local oxygen concentration for photocatalysts at a gas-liquid-solid triphase interface is much higher than that dispersed in a bulk liquid phase. Photocatalyst consisting of Au/TiO 2 nanoparticles supported at triphase interface shows a non-diffusion limited charge separation for oxygen photoactivation, therefore achieving a photodegradation efficiency of about 85% toward bisphenol A. Furthermore, we develop a flowing triphase photocatalytic system that exhibits a tunable one-way photodegradation efficiency from 10% to 60% and a photostability for up to 50 h of continuous irradiation, further demonstrating the potential for large-scale applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Qinglin Yin,Hongji Chen,Shihao Ding,Qi He,Xiahui Gui,Yaowen Xing
Fluidized bed flotation involves three phases of gas, liquid and solid, which can be used for the separation of coarse minerals. In this study, a two-dimensional gas–liquid-solid fluidized bed was developed to explore the fluidization characteristics of fluidized bed flotation. The effects of water velocity, air velocity, frother dosage and particle size (Q l , Q g , ρ n , D p ) on the average pressure drop (–ΔP) and standard deviation (σ ΔP ) were investigated. As the water velocity increases, the pressure drop initially increases, subsequently decreases and eventually remains constant. Increasing the air velocity will enhance the resistance of the bed to the water flow, resulting in a reduction in the water velocity required by peak pressure drop. Furthermore, the pressure drop is observed to decrease due to an increase in air velocity after reaching complete fluidization. Increasing the particle size has the opposite effect, while variations in frother dosage only influence the peak pressure drop. According to the bubble behavior, the influence of different conditions on the pressure drop fluctuation was analyzed. Increasing the water velocity, the frother dosage and the particle size contribute to a reduction in pressure drop fluctuation, whereas an increase in air velocity has the opposite effect. When the water velocity exceeds 1.2 L/min and the frother dosage exceeds 80 g/t, the pressure drop fluctuation is basically unchanged. Finally, the response surface methodology was used to analyze the interaction among the variables, and a mathematical model of the correlation coefficient was established to predict effects.
研究领域:
矿物加工工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yanjiao Xu,Mengbo Zhang,Hengyu Zhong,Shuying Xie,Xuxin Zhu,Haomiao Zhang,Jingdai Wang,Yongrong Yang
We present a 3D-printed stackable miniature membrane reactor to handle gas–liquid-solid reactions effectively and showcase its application in the synthesis of alkylaluminoxanes. The combination of membrane dispersion and microreaction techniques allows for better process control of the ultrafast and highly exothermic reactions of alkylaluminums hydrolysis with pyrophoric reactants. Droplet generation experiments guide the optimization of the reactor structure and operating parameters, highlighting its ability to produce clustered microdroplets with a narrow size distribution and minimal energy consumption. Our visualized reactor design provides insights into the transient characteristics of alkylaluminoxanes formation, improving understanding of the complex chemistries and achieving room-temperature synthesis of highly active methylaluminoxane (MAO) and isobutylaluminoxane (IBAO) for ethylene polymerization. When scaled up, our compact and integrated five-layer stacked reactor demonstrates uniform flow distribution and consistent reaction performance among all layers, achieving an impressive production rate exceeding ten tons/year. Our work demonstrates a versatile membrane microreaction platform for the scalable and inherently safe production of highly reactive materials, offering a promising approach for other challenging chemical synthesis applications.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yuhang Chen,Yaheng Zhang,Hongwei Zou,Minglei Li,Gang Wang,Min Peng,Jie Zhang,Zhiyong Tang
Difficult handling the solid catalysts remains one of the pain points in the continuous flow photochemistry. In this work, the gas–liquid-solid segmented flow was employed in the photocatalytic production of azo- compounds (azoxybenzene and azobenzene) from nitrobenzene using graphitic carbon nitride (g-C 3 N 4 ) as solid catalyst. Compared with the batch reactor, the photocatalytic reaction rate was greatly improved in the microreactor, and the reaction time was shortened from 180 min of the batch to 7.5 min for near-full conversion of nitrobenzene. The effects of various reaction parameters (temperature, light source power, catalyst content) in the continuous system were examined, and the reaction kinetic was found in first order. The photocatalytic reaction performance was very sensitive to the gas–liquid-solid segmented flow conditions, which needed to be carefully tuned. With the help of high-speed camera and micro particle image velocimetry (µ-PIV) techniques, it was identified that the increasing inert gas fraction resulted in more stable segmented flow with shorter liquid segments, favoring the reaction rate. With a high gas fraction, the intensity of recirculation in the liquid segments was strengthened by the increasing total flow rate, enhancing the local mass transfer, thereby benefiting the photocatalytic reaction. Overall, the continuous microreactor reached 5.6 times higher productivity per volume (26.1 mmol/h*L) of azo- compounds than the batch reactor under the same conditions. The successful photosynthesis of azo- compounds demonstrated the great potential of the presented gas–liquid-solid segmented flow, and the findings of this work provide useful guidance on its future application in other heterogeneously catalyzed reactions.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2020
·Vol. 5
·期 9
·1751-1758
·
IF 3.441
Xiaonan Duan,Jiacheng Tu,Andrew R. Teixeira,Le Sang,Klavs F. Jensen,Jisong Zhang
An automated flow platform based on a tube-in-tube contactor and micro-packed bed reactor is developed to measure the kinetics of gas–liquid–solid hydrogenation reactions. The liquid flowing in the inner tube of the tube-in-tube contactor is rapidly saturated to ensure a constant H2 concentration before entering the micro-packed bed, which transforms the gas–liquid–solid system into a liquid–solid system. A ramping strategy is adopted in which the continuously varied residence time and the corresponding conversion data are obtained in a single experiment. Two reactions including hydrogenation of α-methylstyrene and nitrobenzene are chosen to demonstrate the accuracy and efficiency of this automated platform. Varying the flow rate ramping shows that accurate kinetic determination requires a specific range of flow rate ramps. A kinetic curve of conversion versus residence time (more than ten thousand data points) can be obtained in a single experiment within 50 min. The kinetic parameters obtained with this strategy agree well with literature values. The automated flow platform with flow rate ramping enables accurate determination of gas–liquid–solid reaction kinetics with higher efficiency and lower reagent cost compared with other methods.
研究领域:
化学工程
·
反应动力学
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2021
·Vol. 7
·期 3
·590-598
·
IF 4.239
Runzhe Liang,Xiaonan Duan,Jisong Zhang,Zhihong Yuan
In recent years, self-optimization strategies have been gradually utilized for the determination of optimal reaction conditions owing to their high convenience and independence from researchers' experience. However, most self-optimization algorithms still focus on homogeneous reactions or simple heterogeneous reactions. Investigations on complex heterogeneous gas–liquid–solid reactions are rare. Based on the Nelder–Mead simplex method and Bayesian optimization, this work proposes a reaction optimization framework for optimizing complex gas–liquid–solid reactions. Three gas–liquid–solid reactions including the hydrogenations of nitrobenzene, 3,4-dichloronitrobenzene, and 5-nitroisoquinoline are investigated, respectively. Reaction parameters (temperature, hydrogen pressure, liquid flow rate, and gas flow rate) are optimized. Compared with the traditional OVAT method, the proposed Bayesian based optimization algorithm exhibits remarkable performance with higher yields (0.998, 0.991 and 0.995, respectively) and computational efficiency.
研究领域:
化学工程
·
人工智能应用
✓ 已验证
产品关联
DOI
高影响因子
Matter
·
2021
·
IF 15.589
Wei Qian,Xiuwen Xu,Jian Wang,Yangbing Xu,Jianwei Chen,Yongshuai Ge,Jun Chen,Shuang Xiao,Shihe Yang
Medical X-ray computed tomography requires imaging at a low dose rate and in a large area. Halide perovskites have shown high potential for X-ray detection, but a pressing challenge is the current lack of low-cost methods for large-scale fabrication of high-quality thick perovskite films. Here we demonstrate and elucidate an aerosol-liquid-solid process to enable continuous growth of uniform halide perovskite films at low temperature over a large area of 100 cm 2 , which are vertically monolithic, and thus beneficial to carrier transport. Direct-conversion X-ray detectors based on the representative CsPbI 2 Br films in conjunction with a deliberated, interface-engineered C-electrode have realized an unprecedented sensitivity (≥1.48 × 10 5 μC Gy air −1 cm −2 ) and a low limit of detection (280 nGy air s −1 ). We have further demonstrated the high-resolution radiographic imaging capability of these films. These results lay the groundwork for large-scale application of halide perovskites in radiation detectors.
研究领域:
材料科学
·
医学影像
·
辐射探测
✓ 已验证
DOI
高影响因子
SURFACE AND INTERFACE ANALYSIS
·
2022
·Vol. 55
·期 4
·279-287
·
IF 1.702
Mengnan Qu,Bin Zhang,Yandong Wang,Yanqing Lv,Jianwei Ge,Yaxin Wu,Min Yan,Lei Shen,Jinmei He
Wettability is an important property of solid surfaces, superwetting materials can be prepared by controlling the surface morphology and surface energy. In recent years, superwetting materials have been researched and used widely in the fields of self-cleaning, anti-fogging, microfluidics, and oil–water separation, but few studies about superwetting materials in chemical reactions have been conducted. In the multiphase reaction, the low solubility and diffusion rate of gas lead to inferior mass transfer, which restricts the reaction kinetics and reduces the reaction rate. Therefore, it may be a breakthrough to make the solid surface obtain underwater superaerophilicity. In this paper, 1H,1H,2H,2H -perfluorooctyltriethoxysilane (POTS) with low surface energy was constructed on the palladium-carbon nanotubes (Pd-CNTs), as-prepared Pd-CNTs/POTS composite has excellent hydrophobicity and underwater superaerophilicity. When Pd-CNTs/POTS composite was utilized in the catalytic hydrogenation, Pd-CNTs/POTS composite shows higher catalytic activity than Pd-CNTs; the higher catalytic performance is attributed to the underwater superaerophilicity, which enables gaseous hydrogen to rapidly accumulate on the surface of material, increasing the gas–liquid–solid reaction interface formed. The strategy looks forward to providing a new way for developing novel and efficient heterogeneous catalysts and reaction systems.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）