JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Zhongshan Ren,Xiaojun Hu,Xiangxin Xue,Kuochih Chou
The solid state reactions in Fe 3 O 4 –TiO 2 system has been studied by diffusion couple experiments at 1323–1473 K, in which the oxygen partial pressure was controlled by the CO–CO 2 gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-diffusion coefficients in Fe 3 O 4 phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of diffusion layer and temperature, the diffusion coefficient of the Fe 3 O 4 –TiO 2 system was obtained. According to the Arrhenius equation, the estimated diffusion activation energy was about 282.1 ± 18.8 kJ mol −1 .
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Peini Xie,Xueqin Liao,Jianzhong Liu
To improve the combustion characteristics of micron-sized aluminum (Al) powder, a composite powder was prepared by doping a small amount (15 wt%) of magnesium fluoride (MgF 2 ), polytetrafluoroethylene (PTFE), and fluorinated graphite (FG) into the aluminum powder through solution dispersion method. The physical phase composition, micro morphology, thermal reactivity, and combustion performance of the composite powders were also characterized. The findings suggest that the promoting effect of the three fluorides on aluminum combustion can be ranked in the following descending order: FG > PTFE > MgF 2 . The fluorides can to erode the Al 2 O 3 shell layer directly, thus creating cracks and reaction pathways for the Al core enclosed within the shell. Moreover, the gasification of AlF 3 within the combustion products can escape from the surface of Al particles and promote the oxidation combustion of the exposed aluminum, which enhances the diffusion reaction on the active aluminum surface.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Bo-Jun Zeng,Si-Ming Wu,Ge Tian,Ming-Bin Gao,Li-Ying Wang,Lu Wu,Xuan Wu,Liang Mao,Gang-Gang Chang,Christoph Janiak,Xiao-Yu Yang
The exceptional performance of hierarchical zeolites is closely related to the diffusion process for applications in oil refining and chemical synthesis. However, the knowledge of structure-diffusion-reactivity relationships, and particularly the dynamically evolving data of guest molecules in catalysis, for hierarchical zeolites is still incomplete. Herein, a dual structure-directing agents’ strategy is used to synthesize hierarchical ZSM-5 with fish scale-like micro-nano structures (F-ZSM-5) in fluoride medium. The structure-diffusion-reactivity relationships of F-ZSM-5 and conventional ZSM-5 crystals while catalyzing the oligomerization of furfuryl alcohol are elucidated by using an in situ microimaging technique. Additionally, distinct differences of catalytic performance are observed in individual zeolite crystals due to their different nano-architectures, suggesting the high correlation between diffusion and reaction rate and crystal morphologies. Observations made in this investigation deepen the understanding of molecular transport in zeolites and provide guidance for the rational design of desired nanostructures that lead to optimal catalytic properties.
研究领域:
材料科学
·
催化化学
·
纳米结构设计
·
多孔材料
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2018
·Vol. 44
·期 5
·3597-3611
·
IF 1.674
Zhou Xiao,Cao Limei,Yang Ji
An electrode in situ catalytic oxidation of elemental mercury (Hg 0 ) in flue gas using Fenton-like catalysts in a self-made reactor was proposed. The catalysts were prepared by a hydrothermal method, and the catalysts were loaded on the electrode and could improve the removal efficiency of Hg 0 . About 240 μg/m 3 of elemental Hg 0 could be removed in 40 min. The morphology and structure information of the prepared catalysts were characterized by SEM, EDS, XRD, SEM, XPS and so on. The effects of operation parameters (voltage, inlet flow, electrolyte concentration, initial concentration of Hg 0 , pH of solution) were investigated. The above results showed the strong oxidative effect of hydroxyl radicals (·OH), which was produced by the catalysts playing a dominative role during Hg 0 removal reactions. Graphical
研究领域:
环境化学
·
大气污染控制
·
电化学工程
·
催化科学与技术
·
环境功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Yijun Xue,Wei Sun,Qian Wang,Limei Cao,Ji Yang
MOFs (metal-organic frameworks) are stable materials with both organic and inorganic pores, and possess high surface area fascinating structures. Owing to the unique octahedral of aluminum center and strong Al–O bonds, Al-based MOFs show excellent thermal stability. In this paper, MIL-96(Al) is proved to be effective at dispersing Pt particles evenly and sparsely as it is employed as catalyst support. MIL-96(Al) is synthesized via a water based route and different contents of Pt particles are directly deposited on the surface of MIL-96 in one step by hydrothermal method to prepare Pt X MIL-96 (x represents Pt content) catalysts. The catalyst are sprayed evenly on carbon paper, with Pt content of 0.03%, 0.11%, 0.27% and 0.41%, respectively, and are applied in a gas diffusion reactor with snakelike flow field for low temperature H 2 -SCR. For Pt 5 MIL-96/CP, the NO removal efficiency can reach up to 100% at 60 °C. Electron transfer between Pt and MIL-96 is observed via X-ray photoelectron spectron (XPS). It reveals that the deposited Pt is in metallic state. Meanwhile, the electronic structure of MIL-96 is kept intact in the process of Pt depositing. The excellent performance of Pt 5 MIL-96/CP catalyst strongly suggests its potential application.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Xiaozhuo Chen,Yan Wang,Nan Hai,Jianlei Lu,Xi Chen,Jiawei Zhang
Intelligent hydrogel actuators that can display stimuli-responsive shape transformations have attracted tremendous interest and shown promising potential applications in many fields. However, it remains a significant challenge to accomplish remotely controllable actuating performance. Herein, an untethered hydrogel actuator fabricated through an interfacial diffusion reaction toward pick-and-place tasks is presented. The anisotropic structures are obtained by generating Fe3O4 nanoparticles in the local regions of a poly(N-isopropylacrylamide) (PNIPAm) hydrogel, leading to complex shape transformation behaviors. The presence of Fe3O4 nanoparticles endows the hydrogel with magnetically responsive navigation and photothermal conversion capacity. Therefore, untethered soft robots capable of realizing pick-and-place tasks were developed. This presented strategy is expected to promote the development of untethered soft robotics toward pick-and-place tasks.
研究领域:
材料科学
·
机器人技术
·
纳米技术
·
软物质物理
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Na Lu,Haibo Lin,Jianqiang Wang,Qiu Han,Fu Liu,Chuyang Y. Tang
Catalytic membrane is an appealing technology for eliminating refractory organic pollutants in comparison to conventional advanced oxidation methods. However, the application of this technology is constrained by the trade-off between membrane permeability and reactivity. Herein, we prepared a tubular macroporous catalytic membrane (MCM), which activated peroxymonosulfate to produce dominant singlet oxygen (1O2) and hydroxyl radicals (•OH) in the macropore channel (∼130 nm). The optimized MCM membrane demonstrated catalytic filtration performance far beyond the state-of-the-art, achieving >99% degradation of antibiotics, dyes, and phenolic compounds while simultaneously exhibiting ultrafast permeance (645.3 L m–2 h–1 bar–1). For the first time, we reveal the spatial distribution of shorter-lived •OH and long-lived 1O2 in the macropore channel via a diffusion-reaction kinetic model, which provides fundamental insights into how these two reactive oxygen species work synergistically to offer opportunities for breaking the permeability–reactivity trade-off. Furthermore, the MCM achieved robust and stable removal of total organic carbon for a real high-salinity wastewater, verifying its practical potential for treating refractory organics.
研究领域:
环境科学
·
化学工程
·
膜技术
·
高级氧化工艺
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Zetan Liu,Jingkun Xu,Xiaoqing Xi,Weijia Luo,Ji Zhou
Since the synthesis of non-oxidized ceramic and alloy powders requires both high temperature and oxygen insulation conditions, here we demonstrate a cost-efficient molten salt sealing/shielded synthesis method with dynamic gas tightness. Compared to conventional synthesis method, it can prevent the loss of reaction materials at high temperature, cut off the connection between reacting material and outside air, and does not require long-time ball milling mixing treatment or provision of applied pressing before or during heating. Only low-cost salts (e.g., NaCl, KCl), a few minutes of raw material mixing, and regular heating molds are required to obtain high-purity (>96 wt%), micron-sized Ti 3 AlC 2 and Ti 3 SiC 2 powders with narrow size distribution, which significantly decreased the complexity and production costs in the synthesis process. The effect of temperature and raw material content on the products were investigated. The mechanism of diffusion reaction between reactants in molten salt environment was analyzed. The new method developed here was also applicable to Ti 2 AlC, V 2 AlC and Cr 2 AlC MAX phases, as well as provided new ideas for the preparation of other MXenes precursors with certain stoichiometric ratios, air-sensitive materials and nanopowders .
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 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）