MICROPOROUS AND MESOPOROUS MATERIALS
·
2023
·
IF 5.2
Shaoxiang Xu,Meihua Zhu,Pengming Huang,Shengao Zheng,Yujie Qiao,Yuan Liang,Xiangshu Chen,Hidetoshi Kita
Nano-size titanium silicalites is difficult to be separate from the reaction solution, lamellar and homogeneous Ti-MWW zeolites are successfully formed a dense zeolite layers on α-Al 2 O 3 pellets by secondary hydrothermal synthesis in this study. Seeded crystals concentration and titanium source have significantly influences on the morphology, thickness and titanium active sites of Ti-MWW zeolites. Doping NH 4 F in the precursor synthesis solution could conducive to prepare macroscopically and anatase-free Ti-MWW zeolites layer on the outside of α-Al 2 O 3 pellets, and the thickness of the Ti-MWW zeolites layer is ca. 1 mm. Besides, catalytic performance of the supported Ti-MWW zeolites are significantly improved by NH 4 F. A fixed-bed reactor with the supported Ti-MWW zeolites are applied to catalyze phenol hydroxylation with hydrogen peroxide efficiently, and reaction time and temperature, amount of the supported Ti-MWW zeolites have obvious effects on the phenol conversion and dihydroxybenzene selectivity. When the actual mass of Ti-MWW zeolites to volume of reaction solution is only 10 g/L, the relative phenol conversion and dihydroxybenzene selectivity are 46.45% and 92.72% at 65 °C after 3 h, respectively.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2021
·
IF 4.311
Mingshuai Sun,Fumin Wang,Jiaqi Hu,Guojun Lv,Xubin Zhang
A highly dispersed and stable PdC phase supported on α-Al 2 O 3 for semi-hydrogenation of acetylene was prepared using N-containing silane coupling agent as a modifier. The catalyst exhibited as much as 15% higher ethylene selectivity than traditional PdAg alloy with full acetylene conversion under 240 °C and performed longer stability within 200 h tolerance test. Characterization results reveal that the excellent ethylene selectivity is mainly derived from the special PdC phase nanoparticle structure with lattice relaxation and distortion. This unique structure makes the catalyst perform weaker adsorption of ethylene, have more abundant spillover hydrogen on the carrier surface and lead a strong interaction between the Pd nanoparticles and surface. Experimental results and DFT calculations have shown the PdC phase is a more promising structure than the commonly used PdAg alloy.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Jiaqin Liu,Chuanyao Liu,Aisheng Huang
Hydrogen has been regarded as the most promising clean and renewable energy. Beside the production of the hydrogen, the separation of hydrogen is also an import issue before it can be used in fuel cells. Membrane-based separation technologies have gained considerable attentions due to its high efficiency and low energy consumption. Zeolite imidazolate framework (ZIF) membranes have drawn intense interest due to their zeolite-like properties such as permanent porosity, uniform pore size and exceptional thermal and chemical stability. It is rather challenged to prepare well-intergrown Co-based zeolitic imidazolate frameworks (ZIFs) membranes on porous α-Al 2 O 3 tubes since Co-based ZIFs prefer to form crystals in the synthesis solution rather than grow as membrane layer on the support surface. In this work, we report the preparation of high-quality ZIF-9 membrane with high H 2 /CO 2 selectivity and excellent thermal stability by using 3-aminopropyltriethoxysilane (APTES) as a covalent linker to modify the α-Al 2 O 3 tube. Due to the formation of covalent bonds between APTES and ZIF-9, ZIF-9 nutrients are bound to the support surface, thus promoting the growth of dense and phase-pure ZIF-9 membrane with a thin thickness of about 4.0 μm. The gas separation performances of the ZIF-9 membrane were evaluated by single gas permeation and mixture gas separation of H 2 /CO 2 , H 2 /N 2 and H 2 /CH 4 , respectively. The mixture separation factors of H 2 /CO 2 , H 2 /CH 4 , and H 2 /N 2 of the ZIF-9 membrane are 21.5, 8.2 and 14.7, respectively, which by far exceeds corresponding Knudsen coefficients. Moreover, the as-prepared ZIF-9 membrane exhibits excellent stability at a relatively broad range of operating temperature, which is beneficial for the industrial application of hydrogen separation or further membrane reactor .
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9
Beibei Liu,Zhigang Wang,Xiaoyao Tan
Compared to organic nanofiltration (NF) membranes, ceramic NF membranes exhibit higher stability under harsh conditions such as extreme pH and elevated temperatures. γ-Al 2 O 3 is commonly employed as an interlayer in multilayer ceramic NF membranes, but it is restricted to relatively mild conditions. In this study, on a macroporous alumina hollow fiber support, a boehmite sol coating is transformed from γ-Al 2 O 3 to α-Al 2 O 3 at a reduced phase-transformation temperature under the induction of TiO 2 , forming a uniform ultrafiltration interlayer for the fabrication of SiO 2 -ZrO 2 separation layer in a single step. By dual regulating the TiO 2 doping content in boehmite sol and sintering temperatures, the resulting SiO 2 -ZrO 2 /α-Al 2 O 3 NF membrane with a pore size of 1.4 nm demonstrates extended stability across a wide pH range of 1–13 under elevated temperatures. During the long-term dynamic textile wastewater treatment test, it maintains stable permeance and selectivity for over 24 h at pH 2/12 under 60 °C, significantly outperforming γ-Al 2 O 3 -supported SiO 2 -ZrO 2 membranes. Meanwhile, it displays a permeance of up to 18 LMH/bar and superior dye desalination performance (CR: 99.23%, NaCl <12%). This optimization strategy not only enhances the stability of SiO 2 -ZrO 2 NF membranes with the aid of an α-Al 2 O 3 interlayer but also provides a simplified route for their fabrication.
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产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2023
·
IF 3.3
Chengyu He,Tie Liu,Peng Miao,Shuang Yuan,Jun Wang,Qiang Wang
Here, we demonstrate that high magnetic fields alter the wettability of water and ionic solutions on the single-crystal α-Al2O3. We investigated the relationship between the substrate crystal orientation, material magnetism, liquid conductivity, and the surface contact angle. Applying high magnetic fields decreased the water contact angles on all of the surface orientations studied, and the reduction was larger for more magnetic substrates. For ionic solutions, high magnetic fields increased the contact angle on the (0001) α-Al2O3 surface but decreased the contact angles on the (112̅0), (101̅0), and (011̅2) surfaces. We attribute these orientation-dependent ionic solution responses to competition between the field-induced sample magnetization energy and the Lorentz force acting on the ionic solution. Overall, this work provides new magnetic-field-based strategies for changing the wettability and provides guidelines for fabricating novel microfluidic systems or biointerfaces with in situ magnetic control.
研究领域:
材料科学
·
物理学
·
化学
·
微流控技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Kang Li,Guoge Zhang,Wenfang Li,Shuoxun Jin,Ken Chen,Aihua Yi,Zhongmiao Liao,Wen Zhu,Yi Huang,Zhisheng Zhu,Min Wang,Jiajing Yang,Rujian Liang
The as-deposit (AD) and heat-treated (HT) Al-Cu alloy obtained via wire arc additive manufacturing (WAAM) technology was coated by plasma electrolytic oxidation (PEO), respectively. The reticular big Al 2 Cu grains in the AD Al alloy substrate evolved into numerous small particles and nano precipitates after the heat treatment. The thickness and surface roughness of the PEO coatings on both substrates were increased gradually with the increase of oxidation time. The coating on the HT Al alloy was deposited faster with a rougher surface structure. Although most Al 2 Cu grains were dissolved in the electrolyte at the earlier oxidation stage, some Cu-containing compounds and metallic Cu were gradually deposited in the coatings at the discharge spark oxidation period. The coatings were mainly composed of γ-Al 2 O 3 and α-Al 2 O 3 , and the ratio of α-Al 2 O 3 was increased obviously with the oxidation time. Besides, the coating on the HT sample consisted of a higher ratio of α-Al 2 O 3 than that on the AD alloy, especially at the end of PEO processing. The PEO coatings were made up of two sub-layers, a thin compact inner layer and a porous outer layer. In comparison, the coating on the HT alloy was a bit denser and more uniform. The substrates displayed a adhesion wear trait while the coated samples shew a slight abrasive wear manner over the abrasion test, with a still ball as the friction pair . and the coated HT alloy had a better wear resistance than the coated AD alloy did.
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Siyi Li,Pinyi Wang,Jianyun Hu,Guangcan Yang,Youjun Lu,Zhenxia Yuan,Xiao Zhang,Sen Liang
γ-AlOOH nanopowder synthesized using hydrothermal-assisted freeze-drying was employed as a precursor, with AlF₃ as a sintering aid, to explore the preparation of α-Al₂O₃ with a high specific surface area at elevated temperatures. The γ-AlOOH nanopowder produced in this study exhibited superior dispersion, achieving a specific surface area of 198.06 m 2 /g and a zeta potential of 45.8 mV. At a calcination temperature of 1200 °C, the resulting α-Al₂O₃, synthesized from γ-AlOOH and AlF₃, maintained a specific surface area of 27.72 m 2 /g, significantly higher than the typical values reported in the literature (generally below 10 m 2 /g). The α-phase purity exceeded 99 %, and the [AlO₆] proportion was 95.07 %. Furthermore, at a calcination temperature of 1150 °C, the specific surface area of the α-Al₂O₃ reached 50.48 m 2 /g. Using this α-Al₂O₃ as a carrier, a composite TiO₂ catalyst was prepared via a sol-gel and hydrothermal method. This catalyst demonstrated a photocatalytic degradation rate of over 98 % for rhodamine B (10 mg/L) within 30 min of irradiation, under the illumination of a 300 W mercury lamp in proximity to the light source.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Huanxu Teng,Meihua Zhu,Yixuan Shao,Siqi Shao,Qingsheng Wu,Ziming Li,Xiangshu Chen,Hidetoshi Kita
Supported TS-1 zeolites were successfully synthesized on α-Al 2 O 3 microsphere by secondary hydrothermal synthesis, which were placed in the fixed-bed reactor and catalyzed the oxidation of isopropanol(IPA) with hydrogen peroxide. Effects of synthesis parameters on the morphology and catalytic activity of the supported TS-1 zeolites were systematically studied in this work. Size of α-Al 2 O 3 microsphere, and crystallization temperature could determine the coverage, titanium coordination, and titanium content of the supported TS-1 zeolites. When the crystallization temperature and H 2 O/SiO 2 molar ratio of the initial synthesis solution were 150 °C and 120, the titanium-rich and anatase-free supported TS-1 zeolites were prepared on the ca. 1 mm α-Al 2 O 3 microsphere support. The supported TS-1 zeolites showed an excellent catalytic performance and stability for isopropanol oxidation, the isopropanol conversion and acetone selectivity reached 100 % within 2 h. Kinetic studies showed that the reaction conformed to the Langmuir-Hinshelwood mechanism and that the apparent activation energy was only 4.57 kJ/mol.
研究领域:
催化化学
·
材料化学
·
化学工程
·
多相催化
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 5
·2140-2155
·
IF 4.5
Zhang Yeguang,Li Yingchao,Liu Wenxin,Li Feihu,Zhan Zili
CH 4 sensors based on metal oxide semiconductors (MOS) provide high sensitivity and fast response, but the sensitivity will be lost when they are poisoned by silicone. Therefore, there is an urgent need to address the poisoning deactivation of MOS gas sensors caused by silicone. Here, the unique strategy of coating a reactive anti-poisoning material onto the surface of the sensing material is proposed to effectively improve the anti-poisoning ability without degrading the gas sensing performance. As an experimental verification, SnO 2 /α-Al 2 O 3 is designed as the anti-poisoning layer and SnO 2 loaded with precious metals (Pt and Pd) as the sensing layer. Owing to the protection of the anti-poisoning layer, the response ( R a / R g = 24.69) and the response/recovery time (1/24 s) of the sensor to CH 4 remained undiminished at 364 °C after being poisoned under an air/hexamethyldisiloxane (HMDSO) (10 ppm) environment for 40 min, which meets the requirements of the Chinese National Standard (GB 15322.2-2019). The mechanism analysis shows that HMDSO can be decomposed with the adsorbed oxygen on the surface of SnO 2 in the anti-poisoning layer, and CH 4 can diffuse into the sensing layer to be detected. The unique anti-poisoning strategies can provide a promising insight for improving the poisoning tolerance of MOS gas sensors. Graphical abstract
研究领域:
材料科学
·
化学工程
·
传感技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Limo He,Song Hu,Long Jiang,Syed Shatir A. Syed-Hassan,Yi Wang,Kai Xu,Sheng Su,Jun Xiang,Lingfeng Xiao,Huanying Chi,Xiaofang Chen
Ni-based catalysts are prone to be deactivated by carbon deposition . This study aims to investigate the influence mechanism of different types of carbon deposition on the activity of Ni/α-Al 2 O 3 catalyst at various steam-to-carbon (S/C) ratios during steam reforming of toluene for hydrogen production . At a low S/C ratio of 1, the catalytic activity of Ni/α-Al 2 O 3 was inhibited due to the covering and blocking of Ni active sites by the formation of amorphous carbon on the Ni surface . While at a high S/C ratio of 3, more than 80 wt% of carbon deposition was found to be self-growth carbon nanotubes (CNTs) with an average diameter of around 15 nm. The activity of Ni/α-Al 2 O 3 in steam reforming of toluene was unusually promoted, which can be attributed to the tip-growth mechanism of CNTs, whereby the Ni particles migrated to the tip or the surface of CNTs, resulting in the improved active site dispersion.
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
Membranes
·
2025
·Vol. 15
·期 2
·54
·
IF 3.6
Yin Yang,Juan Liu,Qi Zhou,Siqi Shao,Lingling Zou,Wenjun Yuan,Meihua Zhu,Xiangshu Chen,Hidetoshi Kita
Silicalite-2 membranes were successfully prepared on tubular α-Al2O3supports by secondary hydrothermal synthesis, and the pervaporation performance of the membrane was evaluated by separation of a 5 wt% ethanol/H2O mixture at 60 °C. The effects of templating agent content, water–silicon ratio and crystallization time on the separation performance of Silicalite-2 membranes were investigated. When the TBAOH/SiO2and H2O/SiO2molar ratios of the precursor synthesis solution were 0.2 and 120, a dense Silicalite-2 membrane could be prepared on the surface of the tubular α-Al2O3support after 72 h. The silane coupling agent was utilized to treat the Silicalite-2 membranes, and the effects of silane coupling agent dosage on their properties were also explored. The pervaporation performance of the Silicalite-2 membrane was greatly improved with a 5.7 wt% trimethylchlorosilane (TMCS) solution and the flux and separation factor of the membrane reached 1.75 kg·m−2·h−1and 22 for separation of 5 wt% EtOH/H2O at 60 °C, respectively.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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