MATERIALS CHEMISTRY AND PHYSICS
·
2024
·
IF 4.3
Shaoqing Wang,Xiangqing Wu,Faqin Xie,Jiayu He,Hao Yu
The innovative work presented in the paper focused on microstructures and wear performance of MoS 2 doped Al 2 O 3 coatings on TC6 alloy. Nano- and micron-sized MoS 2 particles doped Al 2 O 3 coatings (n and m-MoS 2 /Al 2 O 3 coating) were fabricated on TC6 alloy via cathodic plasma electrolytic deposition (CPED) technique. The microstructures and compositions of the coatings were characterized, the tribological behaviors were tested, and doping mechanism of MoS 2 particles was discussed. The results showed that, doped coatings were composed of α -Al 2 O 3 , γ -Al 2 O 3 and MoS 2 . The doping of MoS 2 particles promoted the transformation from γ -Al 2 O 3 to α -Al 2 O 3 during CPED process , and increased the compactness and crystallinity of doped coatings. The friction coefficients of TC6 alloy, Al 2 O 3 coating, n-MoS 2 /Al 2 O 3 coating and m-MoS 2 /Al 2 O 3 coating were about 0.7, 0.6, 0.55 and 0.45 in sequence, and the wear rates of n-MoS 2 /Al 2 O 3 coating and m-MoS 2 /Al 2 O 3 coating were about 75 % and 58 % of Al 2 O 3 coating. MoS 2 particles played the role of lubrication and contributed to improving wear performance of doped coatings, both friction coefficients and wear rates were declined, and micron-sized MoS 2 particles presented better wear performance than nano-sized particles.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Peng Shengpan,Ma Ziran,Ma Jing,Wang Hongyan,Chen Jingyun,Wei Hui,Li Yonglong,Ao Zhimin,Wang Baodong
Pd/Al2O3 catalysts modified by different chemical elements (Mg, Si, Ce, and Zr) were tested for methane (CH4) catalytic combustion, and PdO nanoparticles loaded on modified Al2O3 were systematically studied. These conditions assess the carrier effects of Pd/Al2O3 and acid strength influences on CH4 combustion. We observed carrier effects on activation energy through tuning Pd 3d binding energies (BEs) and on pre-exponential factors (A) through Pd dispersion and acidity on supports. When the BE of Pd 3d5/2 is 337.3 eV, PdO nanoparticles loaded on modified Al2O3 have excellent activity in cracking the C−H bond of CH4, which leads to the lowest activation energy (Ea), regardless of the size effect of the PdO nanoparticle. Furthermore, a theoretical construction that acid sites on catalysts promote the reversible elementary step (2Pd−OH ↔ Pd−O* + Pd* + H2O) right shifts improving the A dependency on the quantity of exposed Pd* and Pd−O*. As a result, Al2O3, as the carrier, not only modifies the electronic characteristics and size of supported PdO nanoparticles but also participates in the reaction process via acid sites on the surface of Al2O3.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Zhiwei Xu,Xiangxing Zhou,Ke Peng,Tiechui Yuan,Ruidi Li,Zhihui Zhou
In this study, fast hot-pressing sintering and the power of B 4 C and 1/3/5/7 wt% Al 2 O 3 were used to make B 4 C-Al 2 O 3 composite ceramics at 2000°C and 30 MPa. The toughening mechanism was thoroughly examined, and the impact of Al 2 O 3 content on the microstructures and mechanical characteristics of B 4 C-Al 2 O 3 composite ceramics was examined. The comprehensive mechanical properties of B 4 C-Al 2 O 3 composite ceramics were optimized by adding 3 wt% Al 2 O 3 , the relative density, flexural strength , fracture toughness, and Vickers hardness reached 99.38 %, 616.2 MPa, 5.45 MPa∙m 1/2 , and 35.91 GPa, respectively. The strengthening mechanism of B 4 C-Al 2 O 3 composite ceramics is that grain refinement and grain boundary movement are hindered by second-phase particles. And the toughening mechanism is crack deflection and Al 2 O 3 grain cracking.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Yuhang Yang,Chuanwen Zhao,Pengxin Zeng,Yuhao Wang,Xue Qin,Yueyue Gao,Yafei Guo,Ruilin Wang,Jian Sun
Suitable molding and granulation methods are crucial, and an outstanding sphere structure can play a better role in the future scale-up industrial application of K 2 CO 3 -based CO 2 adsorbent. Water will form a large contact angle on the surface of hydrophobic solution and become sphericity water. In this work, hydrophobic powders (polyethylene (PE), TiO 2 , and SiO 2 ) were selected in the hydrophobic interface-assisted method. The CO 2 adsorption capacity of TiO 2 pellets is 0.50 mmol/g, while that of PE pellets is 0.24 mmol/g, and finally that of SiO 2 pellets is 0.36 mmol/g. Then, experiment proved that high temperature (>500 ℃) makes the hydrophobic powders (i.e, TiO 2 and SiO 2 ) lose hydrophobicity which make water molecules diffuse faster, while PE is completely decomposed at high temperature. Compared with the pellets calcined at 300 ℃, the TiO2 pellets calcinated at 500 ℃ have an adsorption capacity of 0.70 mmol/g, which is over 1.72 times that of the original pellets, and the other two hydrophobic surfaces are also improved to some extent. Additionally, the appropriate ratio of low-temperature pore forming agent (i.e., urea) can help improve the adsorption performance, while excessive addition will lead to poor CO 2 adsorption performance. In addition, the K 2 CO 3 /Al 2 O 3 pellets also exhibited desirable mechanical properties, with an optimal compressive strength of 41 Mpa. Therefore, the loss of hydrophobicity leads to more active diffusion of water molecules, which may provide a new idea for the future development of CO 2 adsorbents and other areas.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2024
·
IF 2.2
Tu Xuesong,Zhou Hong,Chi Hao,Zhou Jian
Massive heat generated by electronic components during continuous operation will affect the operation of the equipment, so it is of significance to face up to the heat dissipation problem of electronic packaging materials. Epoxy resin (EP) is widely applied to electronic components for its excellent electrical insulation and processability. To improve the thermal conductivity of composites, this study prepared BN-Al 2 O 3 /EP composites by adding a hybrid of modified boron nitride (mBN) and modified alumina (Al 2 O 3 ) into EP. Profiting from the high thermal conductivity and low dielectric constant of BN and Al 2 O 3 , the thermal and dielectric properties of EP composites were improved. Specifically, the composite of 4 wt.% BN-3 wt.% Al 2 O 3 not only occupied the high thermal conductivity 0.25 W/(m K) at 50°C, but also kept the relatively inferior dielectric constant (4.27) and the low dielectric loss (0.0037) at 10 2 Hz. The composite could be applied in electronic packaging materials as it has excellent dielectric properties and high thermal conductivity.
研究领域:
材料科学
·
电子工程
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Jieying Jing,Zhongyuan Guo,Ze Li,Yu Chen,Hao Li,Wen-Ying Li
Ni 2 P/Al 2 O 3 catalysts with phosphate deposition were synthesized by a hypophosphite decomposition method. Benefiting from its spherical structure and special electronic properties derived from the deposited phosphate on the catalyst surface, the Ni-2.5P/Al 2 O 3 catalyst offered remarkable activity and stability towards phenanthrene (PHE) hydrogenation, featuring a high turnover frequency of 44.64 × 10 -3 s −1 . Extensive characterizations revealed that the control of P/Ni molar ratio could change the phosphorus migration pathway and affect the amount of the generated phosphate deposition and then the exposed active sites of Ni 2 P. Density functional theory computations indicated that the deposited phosphate could induce electron transfer from Ni to phosphate, and a certain amount of phosphate deposition can endow Ni with an appropriate electron-deficient state, which can improve the PHE adsorption and result in a facile complete PHE hydrogenation.
研究领域:
催化化学
·
材料科学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Shao-jia Liu,Fa-tang Li,Yi-lei Li,Ying-juan Hao,Xiao-jing Wang,Bo Li,Rui-hong Liu
The mismatches of lattices and energy bands in heterojunction are the dominant factors restricting the generation efficiency of reactive oxygen species (ROS) that are powerful tools for water purification and anti-bacteria. In this paper, the mediated lattice matching role of amorphous Al 2 O 3 is presented for constructing the ternary g-C 3 N 4 /Al 2 O 3 /ZnO heterojunctions, which exhibit higher molecular oxygen activation performance than binary g-C 3 N 4 /ZnO and g-C 3 N 4 /Al 2 O 3 heterojunctions. The oxygen activation ability and the ROS generation were testified by the electron paramagnetic resonance (EPR) measurement, transformation of nitroblue tetrazolium (NBT) and degradation of methylene blue (MB). The ROS include superoxide anion radical ( O 2 − ) and consequent product of hydroxyl radical ( OH). The superior oxygen activation performance of the ternary heterojunctions can be attributed to the lattices matching of the mediated amorphous Al 2 O 3 and the resultant efficient cascade electron transfer.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2014
·
IF 3.679
Yuming Cui,Na Liu,Yifen Xia,Jiangang Lv,Sujuan Zheng,Nianhua Xue,Luming Peng,Xuefeng Guo,Weiping Ding
1-Butene, abundant but inexpensive in industry, can be used to produce more valuable propene and ethene through the well-known metathesis reaction. In terms of catalyst system of molybdena, controlling the interaction between the molybdena and the support is quite crucial. A special support, i.e., well-shaped one-dimensional γ-Al 2 O 3 with uniform diameters of ∼10 nm and lengths of ∼100 nm, has been synthesized via oleylamine-assisted hydrothermal method. The molybdenum oxides are well controlled in sizes of moderate aggregation suitable for 1-butene metathesis with a fairly high rate of propene production (38.9 × 10 −9 mol m −2 s −1 , 30 mol% yield in a single pass) under mild conditions. The status of MoO x species in the catalyst has been investigated by solid state 29 Si MAS NMR, Raman, UV–vis, H 2 -TPR and NH 3 -TPD techniques. The catalyst, highly stable after twelve times of regeneration, is important for practical utilization for the metathesis reactions.
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 53
·80399-80410
·
IF 5.19
Shu Xinpeng,Bi Huaqi,Wang Jun,Yang Jiaxin,Wang Jue,Liu Guangqing,Su Bensheng
Catalytic ozonation with supported metal oxides is a promising strategy for addressing refractory pollutants in wastewater. In this study, γ-Al 2 O 3 supported MnO x -CeO x catalysts (MC 1 , MC 2 , and MC 3 ) obtained at different calcination temperatures (400 °C, 550 °C, and 700 °C) were applied as effective catalysts for ozonation and explored the feasibility of the treatment of oxytetracycline (OTC) wastewater. Comparatively, the MC 2 possessed the highest molar ratios of Mn 3+ /Mn 4+ (1.60) and Ce 3+ /Ce 4+ (0.96), the largest surface area (273.8 m 2 g −1 ) with a petal-shaped structure, and most abundant surface hydroxyls (3.78 mmol g −1 ). These physicochemical characteristics benefited the surface reaction and resulted in the acceleration of ozone decomposition, electron transfer, and •OH generation, thereby improving the catalyst’s adsorption ability and catalytic activity. The combination with MC 2 increased the OTC and COD removal of the ozonation process from 59.1% and 29.0% to 94.7% and 83.3% in 25 min, respectively. By employing electron paramagnetic resonance (EPR) and radical quenching experiments, it was verified that •OH species generation promoted the mineralization of OTC. The possible degradation pathways of OTC were investigated through mass spectrometry, and the route consisted of dehydration, deamination, and demethylation. Moreover, during a 12-day continuous experiment, MC 2 catalyst exhibited excellent reusability and catalytic stability, with COD removal efficiencies above 80%.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 102
·期 7
·3879-3886
·
IF 2.956
Binbin Dong,Mingye Yang,Feihong Wang,JunWei Wang,LuYuan Hao,Xin Xu,Gang Wang,Simeon Agathopoulos
The rapid development of engineering filtering process suggests that it is imperative to produce membrane substrates with a fine pore size, high gas permeation, and antifouling properties for efficient and long-term application. This study reports on a novel fabrication method of a porous Al 2 O 3 /CaAl 12 O 19 ceramic membrane substrate by a direct foaming method combined with cement solidification and tape-casting technology. The microstructure of the produced ceramic membrane consisted of pores with a size of 50-150 μm, which were interconnected with each other with a large number of small filtering functional pores of <10 μm. By increasing the amount of the foaming agent, the porosity of the porous Al 2 O 3 /CaAl 12 O 19 ceramic membranes was tailored from 64.8% to 80.5%, and the bending strength decreased from 32.1 ± 1.0 to 9.6 ± 0.9 MPa, respectively. The sintered hydrophilic ceramic substrate was successfully modified to a hydrophobic one (with water contact angles of 143°) by pyrolysis of dimethyldichlorosilane and dichloromethylsilane. The resultant membrane displayed high chemical stability and self-cleaning features. The membrane with a porosity of 64.8% had a N 2 permeation of 3.0 (±0.5) × 10 7 L m −2 h −1 at 0.5 bar and a water flux which could be totally suppressed at a liquid entry pressure of 0.45 bar.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Liping Zhang,Huitong Li,Mengnan Duan,Weiwei Wang,Ran Mu,Zehua Pi,Yubin Shang
Coking reverse osmosis concentrates (ROCs) are characterized by a high organic content, complex composition, and difficulty in biological degradation. To achieve the zero liquid discharge (ZLD) strategy, ROCs need to be treated urgently. This work aims to prepare a modified catalyst under high-efficiency activated alumina (γ-Al 2 O 3 ) loaded with Fe and Co bimetals and to degrade m-cresol as a typical pollutant in actual coking ROCs. The results showed that Fe and Co metals were successfully loaded. Meanwhile, the catalyst enhances the reactive active sites, reduces the activation energy of the reaction, and improves the degradation efficiency. The degradation mechanism and removal process were investigated. The results showed that with the optimal conditions, as ozone dosage of 50 mg/L, gas flow rate of 400 mL/min, catalyst dosage of 30 g/L, and pH value of 9, the removal rates of COD, TOC, and UV 254 were 75.61 %, 56.22 %, and 84.14 %, respectively. This study provides a better treatment option for the degradation of m-cresols in coking ROCs.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Min-Ping Zhu,Jia-Cheng E. Yang,Darren Delai Sun,Baoling Yuan,Ming-Lai Fu
Reported here is a pioneering work on the co-removal of carbamazepine (CBZ) and metronidazole (MNZ) by Co 2 AlO 4 @Al 2 O 3 millispheres activated peroxymonosulfate (PMS). Compared with the single removal, the reduced ratios for the removal kinetics of MNZ (72.16%) are two times higher than that of CBZ (35.41%) within initial pH 3 – 9. This is essentially due to the higher oxidation affinity of SO 4 •– and 1 O 2 toward CBZ than MNZ. Cl − facilitated the degradation of CBZ but inhibited the degradation of MNZ, probably ascribed to the formation of HOCl and Cl 2 •− . HCO 3 − and PO 4 3− significantly inhibited the removal of CBZ and MNZ by scavenging SO 4 •– and/or passivating the active sites of Co 2 AlO 4 @Al 2 O 3 . The degradation of CBZ is mainly due to the electron abstraction and oxygen addition, while the primary oxidation processes of MNZ include the denitration, ring opening and/or N-C cleavage. Because of the competition of CBZ against SO 4 •− , the simultaneous removal process remarkably changed the main products of MNZ compared with the single removal process. The simultaneous removal of CBZ and MNZ increased the total bioaccumulation potential and mutagenicity risk of degradation products but helped to reduce their total developmental toxicity. The products formed in the co-removal process showed higher total acute toxicity to Daphnia magna than those of the single process, while for the total acute toxicity to Oral rat , the results are reversed. This work will spark more interest of simultaneously removing multiple emerging pollutants with monolithic catalysts-oriented oxidation processes.
研究领域:
环境科学
·
污染控制
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）