INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Zhiming Gao,Lin Cui,Hongwei Ma
Four methods were adopted to prepare samples 20%NiO/Al 2 O 3 with calcination fixed at 500 °C, which were then reduced into 20%Ni/Al 2 O 3 and used as catalysts for reaction of selective methanation of CO in H 2 -rich gas (CO-SMET). XRD and TPR measurements indicate that nickel aluminates were formed in the calcined samples and their formation was influenced by preparation methods. Higher temperatures were required to reduce the calcined samples more efficiently and to achieve a higher catalytic activity for CO-SMET. Among the four methods, the precipitation method using ammonium carbonate as precipitant produced the highest catalytic activity both for CO methanation and for CO 2 methanation after reduction at 800 °C for 2 h. The calcined sample 20%NiO/Al 2 O 3 prepared with the method was therefore used as support and impregnated with Ru 3+ solution. Ru addition promoted reduction of Ni 2+ ions in the calcined sample even at the low temperatures of 400 °C and 500 °C. The catalyst 1%Ru–20%Ni/Al 2 O 3 reduced at 500 °C thus had a superior performance, removing CO to ca. 30 ppm with a selectivity as high as 75% at reaction temperature of 220 °C.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
ACS ES&T Engineering
·
2022
·
IF 0
Xiangyu Ma,Hui Xu,Zhang Liu,Yanfei Liu,Chen Wang,Meiqing Shen,Chun Du,Bin Shan
Catalytic oxidation is a valuable residual methane removal method, and Pd-based catalysts are the most robust and widely applied system. Yet, they suffer from poor stability in practical applications due to sintering and water poisoning. In this work, we prepared a high-performance PdNi/Al2O3 catalyst with PdO-NiO and PdO-NiAl2O4 dual interfaces. PdNi/Al2O3 showed excellent hydrothermal stability after aging at 750 °C, 10% H2O for 72 h, with the T50 remaining below 315 °C. In addition, compared to bare Pd/Al2O3, PdNi/Al2O3 exhibited a better low-temperature activity with a T50 of 287 °C, rivaling state-of-the-art Pd-based catalysts. Combining structural characterizations and DFT calculations, it was shown that dual interfaces promoted the activation of methane C–H bonds and suppressed the adsorption of surface water/hydroxyl groups and agglomeration of PdO particles. This study has provided new perceptions for exploring the influence of interfacial interactions and offered a route to synthesize high-stability palladium catalysts.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xiaohui Yuan,Lei Wen,Chao Wang,Yushun Zhao,Yingchun Zhou,Gong Cheng,Chenxi Zhao,Xiaodong He,Chao Sui
Ceramic fiber materials with high mechanical robustness and outstanding thermal stability are highly sought for high-temperature thermal insulation applications. However, the practical use of traditional ceramic fibrous mats has been hindered by their limited tensile strength, resulting in ceramic fibrous mats being easily deformed or broken under actual conditions. In this study, we present the fabrication of biomimetic, cocoon-like Al 2 O 3 -SiO 2 composite fibrous mats incorporating amorphous SiO 2 , γ-Al 2 O 3 , and mullite phases through the centrifugal spinning technique. The maximum tensile strength of these composite mats is determined to be 5.35 MPa, which is superior to most ceramic fiber materials. Additionally, the Al 2 O 3 -SiO 2 composite fibrous mats demonstrate excellent thermal insulation properties, with a thermal conductivity as low as 0.026 W/(m·K) at room temperature and 0.14 W/(m·K) at 1000 °C. These exceptional characteristics position Al 2 O 3 -SiO 2 composite fibrous mats as promising materials for thermal insulation in industrial, aerospace, and other demanding environments.
研究领域:
材料科学
·
陶瓷
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热工工程
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Tonghe Xing,Annan He,Zhiming Du,Yu Zhang,Yuxin Luo,Zhiyu Huang,Mengqi Wang,Zhicheng Shi,Aixin Tong,Sijie Qiao,Xiaohong Liao,Jie Bai,Heng Pan,Zihui Liang,Wei Ke,Hao Yu,Fengxiang Chen
Silk fiber, as a luxurious textile raw material, is widely used in the textile industry due to its excellent mechanical properties and wearing comfort. However, the poor (ultraviolet, UV) light stability of silk affects its further application in high-end textiles, fashionable apparel, and smart materials. Although surface modification can endow the excellent UV resistance of silk fibers, it often reduces its comfort property. Herein, a laminated ultrathin Al2O3/TiO2 coating with a total thickness of 120 nm is fabricated on the surface of silk fiber via a modified atomic layer deposition (ALD) technique. The tenacity of ALD-coated silk can maintain 61.1% of its original value after exposure to intense UV light (640 mW/cm2) under high temperature (>200 °C) for 6 h, which is far superior to other work that has been reported. This can be attributed to the synergistic effect of the reflection of UV light by the multilayer film barrier, the strong oxidizing free radicals by the Al2O3 layer in the innermost layer, and thermal shield of laminated ultrathin Al2O3/TiO2 film. ALD-coated silk fabrics can also demonstrate a multicycle laundering durability, thermal and chemical stabilities, and flame retardancy. More importantly, the wearing comfort of the modified silk has no obvious change. This method provides principle and technical guidance in high-performance and multifunctional fibers and devices.
研究领域:
材料科学
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纺织工程
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表面改性技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Weichao Wang,Liuying Wang,Gu Liu,Chaoqun Ge,Long Wang,Bin Wang,Jie Huang
Ti 3 SiC 2 exhibits considerable potential for high-temperature microwave absorption due to its relatively high melting point and conductivity. In this study, we successfully prepared Ti 3 SiC 2 /Al 2 O 3 -13%TiO 2 heterogeneous coatings through granulation and plasma spraying techniques. This investigation covered composition, microstructure, oxidation resistance, and a focused analysis of the temperature-dependent permittivity of the coatings. The augmentation in Ti 3 SiC 2 content leads to an escalation in the polarized component, consequently elevating susceptibility to dielectric dispersion. With rising temperature, polarization within the coatings gradually establishes, prompting a transition from polarization relaxation loss to conduction loss as the dominant dielectric loss mechanism. At 5 wt% Ti 3 SiC 2 content, the coating achieves an effective bandwidth of 2.2 GHz at 873 K, with a mere 1.4 mm thickness. Moreover, the coating maintains exceptional oxidation resistance below 700 °C. Ti 3 SiC 2 /Al 2 O 3 -13%TiO 2 coatings manifest as strong contenders for high-temperature microwave absorption applications, and plasma spraying emerges as a promising technique for fabricating high-performance microwave absorption coatings.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Technological Sciences
·
2021
·Vol. 64
·期 6
·1250-1263
·
IF 3.572
Liu XiongZhang,Zhang SenJing,Luo Hui,Chen Fu,Li DongMeng,Wang Xian,Gong RongZhou
The design of the high-temperature microwave absorbing materials (MAMs) with temperature-insensitive and considerable microwave absorption (MA) capacity is a tremendous challenge. TiB 2 -Al 2 O 3 /MgAl 2 O 4 MAMs are prepared by the spark plasma sintering (SPS). Further, the influences of the Al 2 O 3 content on the flexural strength, thermal stability, high-temperature electrical conductivity, dielectric and MA properties are discussed. The results show that the Al 2 O 3 content is associated with flexural strength, high-temperature thermal stability, electrical conductivity, dielectric and MA properties. Meanwhile, the temperature-insensitive and considerable MA properties with the minimum reflection loss (RL min ) ranging from −19.4 to −14.3 dB and the effective absorption bandwidth (EAB, RL<−5 dB) of 3.19–3.55 GHz are attained at 25°C–700°C in 8.2–12.4 GHz as the Al 2 O 3 content increases from 70.6 wt% to 80.6 wt%. This is ascribed to the compensating effect of the positive and negative temperature coefficient materials on the high-temperature electrical conductivity as well as the co-play of the dipolar and interfacial polarization at elevated temperatures. Consequently, TiB 2 -Al 2 O 3 /MgAl 2 O 4 ceramics exhibit the ideal prospect as the high-temperature MAMs.
研究领域:
材料科学
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电子材料
✓ 已验证
DOI
高影响因子
FUEL
·
2024
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IF 6.7
Xianjie Li,Bingxiao Feng,Hailin Zhang,Yaping Liu,Meng Xiao,Tingting Huang,Quanhong Zhu,Hongbing Song
Furfural, a key biomass-derived compound, can be transformed into high-value chemicals, including methyl furoate, through oxidative esterification. This process finds broad applications across various industries. In the current study, gold nanoparticles were deposited on γ-Al 2 O 3 pretreated with NaOH etching, utilizing the urea deposit-precipitation method followed by reduction in a hydrogen atmosphere. This approach resulted in a highly active Au catalyst, which was thoroughly characterized using multiple analytical techniques. The optimization of NaOH etching enhanced the pore structure and improved the dispersion of the active metal on the support. Notably, the Au/γ-Al 2 O 3 -2 catalyst, prepared with a 2-hour etching duration using 1 M NaOH, exhibited uniformly dispersed gold nanoparticles with an average size of 2.8 nm. The smaller particle size and enhanced dispersion of these Au nanoparticles significantly contributed to the catalyst’s superior catalytic activity and recyclability. Under optimized reaction conditions, the Au/γ-Al 2 O 3 -2 catalyst achieved nearly complete conversion of 1 mmol of furfural to methyl furoate within 4 h, with both conversion and selectivity exceeding 99 %. The study also proposed a mechanism for the oxidative esterification of furfural to methyl furoate catalyzed by Au/γ-Al 2 O 3 -2. Additionally, the catalyst’s effectiveness in the oxidative esterification of various substrates was investigated, demonstrating its robust activity for aromatic aldehydes and alcohols. This broadens the potential applications of the catalyst in the synthesis of diverse valuable esters.
研究领域:
催化化学
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生物质转化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2020
·Vol. 53
·期 16
·164002
·
IF 3.169
Xinbo Zhu,Xueli Hu,Xiqiang Wu,Yuxiang Cai,Hongbin Zhang,Xin Tu
In this work, ammonia (NH3) synthesis from N2 and H2 was carried out in a packed-bed dielectric barrier discharge (DBD) reactor, while three kinds of commercial packing materials including acidic γ-Al2O3, alkaline γ-Al2O3 and neutral alumina pellets were employed. The effect of packing materials on plasma-assisted NH3 synthesis was investigated and compared with an unpacked DBD reactor. The results show that the presence of packing materials enhanced the plasma-assisted NH3 synthesis by 15.6% to 44.4% compared to the plasma reaction without a packing. The highest NH3 concentration of 1565.5 ppm was obtained over the alkaline γ-Al2O3 packed plasma reactor. The improvement of packing materials on plasma-assisted NH3 synthesis followed the order of alkaline γ-Al2O3 > neutral γ-Al2O3 > acidic γ-Al2O3 > blank tube only. A series of characterizations were performed to illustrate the structure-performance relationships between plasma-induced NH3 synthesis process and packing materials. The results showed that the basicity of the packing materials played an important role in the plasma-assisted NH3 synthesis process. The reaction mechanisms of NH3 synthesis in the packed-bed DBD reactor were also discussed.
研究领域:
化学工程
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材料科学
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等离子体化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 13
·4341-4349
·
IF 9.48
Yuxue Xiao,Qingwei Meng,Xiaoli Pan,Chao Zhang,Zaihui Fu,Changzhi Li
para-Xylene (PX) is a basic building block of polyethylene terephthalate, which is currently produced from petroleum resources. Developing a renewable route to PX is highly desirable to address both economic and environmental concerns. Several attempts used noble metal catalysts, e.g. Pd/Al2O3, to synthesize PX from biomass-derived 4-methyl-3-cyclohexene-1-carboxaldehyde (4-MCHCA), but suffered from a severe decarbonylation reaction, resulting in toluene as the main product. In this paper, we report an FeOx modification strategy to suppress the decarbonylation reaction on a Pd/Al2O3 catalyst, leading to a drastic shift in selectivity towards PX with a yield up to 81% via a cascade dehydroaromatization–hydrodeoxygenation (DHA–HDO) pathway. Characterization and control experiments revealed that the electron density of Pd sites decreased in an FeOx-modified Pd/Al2O3 catalyst compared to Pd/Al2O3, thus tuning the preferential adsorption mode of the substrate from η2-(C,O), the key transition state of the decarbonylation reaction, to the η1-(O) mode that favors the hydrodeoxygenation process. Notably, this designed catalyst is highly stable and is readily applicable in the selective synthesis of a broad range of desired aromatic chemicals via the same DHA–HDO pathway from cyclohex-3-enecarbaldehyde derivatives. Overall, this work develops a controllable catalyst modification strategy that tailors an efficient catalyst for petroleum-independent bio-PX synthesis.
研究领域:
催化化学
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可再生资源化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Qun Yuan,Hong-Hua Ge,Jun-Yi Sha,Le-Tian Wang,Chuan Wan,Feng Wang,Kai Wu,Xin-Jing Meng,Yu-Zeng Zhao
The influence of Al 2 O 3 nanoparticles on the corrosion behavior of brass in simulated cooling water (SCW) with or without sodium dodecyl benzene sulfonate (SDBS) was investigated by means of electrochemical impedance spectroscopy , polarization curves, scanning electron microscope, energy spectrum analysis, X-ray diffraction and Fourier transform infrared spectroscopy . Results indicate that the brass suffered severe corrosion in SCW and the SCW-Al 2 O 3 nanofluid. The main corrosion product was Zn 5 (OH) 6 (CO 3 ) 2 . Al 2 O 3 nanoparticles promoted both anodic and cathodic processes in the brass electrode, and dezincification was most serious in the SCW-Al 2 O 3 nanofluid. The adsorption of SDBS on the brass surface was enhanced, and a more compact protective film was formed on the brass surface in the SCW-Al 2 O 3 -SDBS nanofluid. As a result, the corrosion resistance of brass was increased in this medium.
研究领域:
材料科学
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电化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Junji Chen,Heshan Cai,Tianxiang Zhao
Aluminium oxide (Al 2 O 3 ) is a promising catalyst support due to its excellent stability, high specific surface area, low price, and wide applicability. At present, most of the synthesis methods of Al 2 O 3 are wet chemical process, and the solid-state synthesis of catalysts is underdeveloped under solvent-free conditions. In this study, we proposed a novel strategy for solvent-free synthesis of Rh/Al 2 O 3 catalysts via mechanochemistry. The pore properties of the catalysts can be tuned by simply adjusting the amount of template CTAB and calcination temperatures. As a proof of concept, as-prepared catalysts are used to catalyze hydrolytic dehydrogenation of ammonia borane. The best catalyst Rh/Al 2 O 3 -CTAB(0.4)-500 achieves a total turnover frequency of 186.0 mol H2 ·mol Rh −1 ·min −1 at 298 K and the activation energy is 44.8 kJ·mol −1 . It also exhibits good cycling properties for catalyzing the hydrolysis of ammonia borane completely even after five runs. The catalysts were also characterized by various methods, including SEM, TEM, XPS, XRD, etc., to study the relationship between their structure and catalytic performance. The results show that the high activity of the catalyst is closely related to its large BET specific surface area and appropriate average pore size.
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
International Journal of Applied Ceramic Technology
·
2023
·
IF 2.1
Mengwen Zhang,Na Cao,Fanyu Meng,Lutong Yang,Binyang Jiang,Jinsheng Li,Lei Fan,Shoulei Yang
High-toughness Al 2 O 3 –Ti(C,N) composites reinforced by cBN particles were prepared by the new oscillating pressure sintering technique. The density, phase, and microstructure evolution of the Al 2 O 3 –Ti(C,N)-cBN composites sintered at different temperatures were studied, and their effects on the mechanical properties were investigated. The results show that when the sintering temperature increases from 1300 to 1500°C, the heat preservation time shortens, whereas the density and interface bonding strength of the composites increase. In addition, cBN particles can play the role of crack bridging and be pulled out when the composites fracture, improving the toughness of the Al 2 O 3 –Ti(C,N)–cBN composites. However, when the sintering temperature further rises to 1600°C, a new phase of TiB 2 forms, and the solid solubility of C and N in Ti(C,N) increases, leading to a decrease in density and mechanical properties. As a result, when the Al 2 O 3 –Ti(C,N)–cBN composite is sintered at 1500°C, its mechanical properties reach the maximum values of 21.5 GPa, 5.7 MPa m 1/2 , and 731 MPa for hardness, fracture toughness, and flexural strength, respectively.
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
危险品化学品经营许可证（带存储）