APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Pengjing Chen,Guofeng Zhao,Ye Liu,Yong Lu
A series of Ni 5 Ga 3 / m -SiO 2 /Al 2 O 3 /Al-fiber ( m = 0, 0.5, 1.0, 3.0 and 5.0 wt%) catalysts have been developed for CO 2 hydrogenation to methanol at ambient pressure. Microfibrous-structured SiO 2 /Al 2 O 3 /Al-fiber supports are obtained though endogenous growth of free-standing boehmite (AlOOH) nanosheets onto a three-dimensional (3D) network of 60 μm-Al-fiber thin felt with the aid of steam-only hydrothermal oxidation reaction between Al metal and H 2 O (2 Al + 4H 2 O → 2 AlOOH + 3H 2 ), followed by calcination and SiO 2 -modification using silica sol. The bimetallic Ni 5 Ga 3 nanoparticles are then placed onto the pore surface of as-obtained SiO 2 /Al 2 O 3 /Al-fiber support by co-impregnation method using Ni and Ga nitrates as precursors followed by reduction in H 2 at 630 °C. The promising Ni 5 Ga 3 /1-SiO 2 /Al 2 O 3 /Al-fiber catalyst is capable of converting 2.3% CO 2 into CH 3 OH with a high selectivity of 86.7% as well as 10.3%/3.0% selectivities to CO/CH 4 at 210 °C, for a feed of CO 2 /H 2 /N 2 (2/6/1, molar ratio). Such microfibrous-structured catalyst design combines the promising catalytic performance of Ni 5 Ga 3 with the enhanced heat transfer and high permeability of the Al 2 O 3 /Al-fiber support. The effect of SiO 2 loading on the formation of Ni 5 Ga 3 alloy nanoparticles is also discussed.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Hongmei Qin,Ziwei Li,Shiyu Qin,Yanda Jiang,Man Liu,Ling Zhou,Siyu Yu,Shan Wang,Chuanxi Xiong
High-temperature polymer dielectric capacitors are urgently needed in the new-generation electronic and electrical systems. Whereas, current commercial polymer represented by polyimide (PI) suffer from exponentially growing conduction loss at high temperatures and high electric fields, and hence extremely low discharged energy density and sharply declined charge-discharge efficiency. In this work, we developed superior Al 2 O 3 /PI/Al 2 O 3 sandwich films with drastically improved capacitive energy storage performance via atomic layer deposition (ALD) technology. Notably, resultant PI hybrid dielectrics deposited by 130 nm-thickness Al 2 O 3 (Al 2 O 3 /PI/Al 2 O 3 -130nm) exhibits the highest breakdown strength and the lowest leakage current density compared to pristine PI. Consequently, Al 2 O 3 /PI/Al 2 O 3 -130nm delivers a discharged energy density of 4.9 J/cm 3 at 25 °C and 3.3 J/cm 3 at 150 °C, as high as 2.7 times and 3.3 times respectively that of near PI film. Moreover, PI hybrid dielectrics can operate steadily under 200 MV/m and 150 °C during 10,000 cycle measurements. The excellent performance is mainly attributed to the improved barrier height of the electrode/PI interface endowed by deposited large-bandgap Al 2 O 3 .This work provides a scalable approach to enable excellent high-temperature energy storage performance of polymer dielectrics and promising to promote the application of PI for capacitive energy storage under harsh conditions.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yixi Wang,Wenqing Xu,Chaoqun Li,Yang Yang,Zanbu Geng,Tingyu Zhu
Gaseous ammonia (NH 3 ), especially that emitted from selective catalytic reduction with NH 3 (NH 3 –SCR) units in the atmosphere is potentially harmful to both human health and the environment. The noble metal catalytic oxidation technology placed behind the SCR unit has been considered to be a promising method for decreasing NH 3 slip. In this study, we prepared Ir/Al 2 O 3 catalysts using two different crystal structures of Al 2 O 3 (α–Al 2 O 3 or γ–Al 2 O 3 ) as supported by an impregnation method and evaluated the performance of the selective catalytic oxidation of NH 3 (NH 3 –SCO). We found that the Ir/γ–Al 2 O 3 catalyst performed better than the Ir/α–Al 2 O 3 catalysts, with 99% of NH 3 converted at 260 °C. The X–ray absorption fine structure revealed that the active species on the Ir/Al 2 O 3 catalysts are mainly oxidized IrO 2 . High–angle annular dark–field images of aberration–corrected scanning transmission electron microscopy revealed that IrO 2 species over 1 nm in diameter are beneficial for activity. In situ diffuse reflectance for infrared Fourier transform spectroscopy studies suggested that the differences in NH 3 –SCO activity were caused by the activity of reactive oxygen species, and the formation of –NH 2 may be the decisive step of the NH 3 oxidation reaction.
研究领域:
催化
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2018
·Vol. 33
·期 2
·381-388
·
IF 0.524
Shi Minxian,Chen Xia,Fan Shanshan,Shen Shirley,Liu Tianxiang,Huang Zhixiong
Fluxing agents of zinc borate, antimony oxide, galss frit A and glass frit B, with different melting or softening point temperatures, were added into MgO-Al 2 O 3 -SiO 2 /boron phenol formaldehyde resin (MAS/BPF) composites to lower the formation temperature of eutectic liquid phase and promote the ceramification of ceramifiable composites. The effects of fluxing agents on the thermogravimetric properties, phase evolution, and microstructure evolution of MAS / BPF composites were characterized by TG-DSC, XRD and SEM analyses. The results reveal that the addition of a fluxing agent highly reduces the decomposition rate of MAS / BPF composites. Fluxing agents lower the formation temperatures of liquid phases of ceramifiable MAS / BPF composites obviously, and then promote the ceramification and densification process. The final residues of composites are ceramic surrounded by large amount of glass phases.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 36
·24944-24954
·
IF 3.9
Lin Li,Tao Zeng,Hongyu Huang,Jun Li,Noriyuki Kobayshi,Xiaohu Yang
In this study, the influences of nano γ-Al2O3 on the thermal storage performance of LiCl were experimentally investigated. The XRD results show that a complex of lithium aluminium oxychloride (LiAlOCl2) was formed through the LiCl·H2O and γ-Al2O3 composites preparation process. The in situ diffuse reflectance infrared Fourier transform spectroscopy measurement reveals that the addition of γ-Al2O3 accelerated the hydration rate of LiCl composites, concentrated the spectrum utilization range, and promoted the desorption rate of physical adsorbed H2O and low-frequency structural –OH in the materials. The highest specific surface area of the composite is 34.5 times higher than that of pure LiCl. The addition of γ-Al2O3 can increase the conversion rate of LiCl·H2O to approximately 100% at the hydration time of 1 h and the addition content of γ-Al2O3 at 15 wt%. A maximum heat storage density (HSD) for the LiCl·H2O-γ-Al2O3 composite can reach 714.7 kJ kgLiCl·H2O−1 in 1 h when the addition content of γ-Al2O3 was 15%wt and its water uptake can reach 0.26 g g−1 in 1 h. It also can be found that the addition of Al2O3 in LiCl resulted in a decrease of the activation energy from 90.89 kJ mol−1 to 79.76 kJ mol−1. However, the thermal conductivity of the LiCl·H2O-γ-Al2O3 composite slightly decreased with the increase of nano γ-Al2O3 content.
研究领域:
材料科学
·
能源存储
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Hongming Fu,Kaili Xue,Jihao Yang,Zhaohao Li,Heng Zhang,Dan Gao,Haiping Chen
In this paper, Al 2 O 3 ceramic membrane is modified to hydrophobicity by grafting 1 H,1 H,2 H,2 H-perfluorodecyltriethoxysilane. And its properties are characterized in detail. CO 2 capture performance of ceramic membrane is investigated by experiments. Results show that wetting resistance after modification is significantly improved, and contact angle increases from the initial 49.8–130.9°. However, hydrophobic modification has no significant effect on the crystalline phase, surface morphology and pore size distribution of the ceramic membrane. With ethanolamine (MEA) as absorbent, CO 2 mass transfer rate and capture efficiency using modified hydrophobic ceramic membrane are 46.6 × 10 −3 mol/(m 2 ·s) and 98.0%, showing significantly increase compared to the original membrane. After 72 h immersion in MEA solution, quality of ceramic membrane does not change significantly. And there is almost no change in average pore size. We believe this study will provide a reference for the industrial application for CO 2 capture by gas-liquid membrane contactor with ceramic membrane.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
Atmosphere
·
2022
·Vol. 13
·期 2
·333
·
IF 3.11
Chao Wang,Lingdong Kong,Shengyan Jin,Lianghai Xia,Jie Tan,Yuwen Wang
Soot and aged soot are often found to be mixed with atmospheric particles, which inevitably affect various atmospheric heterogeneous reactions and secondary aerosol formation. Previous studies have investigated the heterogeneous reaction of NO2with different types of soot, but there are few studies on the heterogeneous reaction of NO2with mixtures containing diesel soot (DS) or aged DS and mineral dust particles. In this study, the effects of DS and aged DS on the heterogeneous reaction of NO2on the surface of γ-Al2O3were investigated via in-situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS). The results showed that the DS or DS n-hexane extract significantly inhibited the formation of nitrate on γ-Al2O3particles and promoted the formation of nitrite. At 58% RH, with the increase of DS or DS n-hexane extract loading amount, the effect of DS or DS n-hexane extract on the formation of nitrate changed from promotion to inhibition, but DS or DS n-hexane extract always promoted the formation of nitrite. The results also showed that light was conducive to the formation of nitrate on the DS-γ-Al2O3or DS-n-hexane extract-γ-Al2O3particles. Furthermore, the influence of soot aging on the heterogeneous reaction of NO2was investigated under light and no light. In the dark, O3-aged DS-γ-Al2O3or O3-aged DS-n-hexane extract-γ-Al2O3firstly inhibited the formation of nitrate on the mixed particles and then promoted it, while the effect of aged DS on nitrite formation was complex. Under light, the O3-aged DS-γ-Al2O3firstly promoted the formation of nitrate on the mixed particles and then inhibited it, while the O3-aged DS-n-hexane extract-γ-Al2O3promoted the formation of nitrate on the mixed particles. Our results further showed that the production of nitrate on the O3-aged particles under light or no light was greater than that of the UV-nitrate-aged particles. This study is helpful to deeply understand the atmospheric chemical behavior of soot and the heterogeneous conversion of atmospheric NO2.Keywords:soot;NO2;heterogeneous reaction;aged soot;γ-Al2O3
研究领域:
大气化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 35
·14656-14664
·
IF 3.5
Di Wen,Ruige Yuan,Fan Yang,Rong Chen
Wearable devices hold significant potential in healthcare and medical diagnostics. One major challenge in realizing this potential is the low barrier property of polymer substrates, which fail to withstand surrounding moisture and biofluids. In this work, a two-step strategy involving ALI followed by a UV-curing process is developed to fabricate a K48PDMS/Al2O3 ultra-barrier with high barrier property of 7.82 × 10−5 g m−2 day−1 under stretching strain, representing one of the highest values among current works. Moreover, the K48PDMS/Al2O3 barrier enables Ca-tested devices to exhibit extended operational lifetimes of up to 12 days in simulated rain. It also ensures the high sensitivity of strain sensors for real-time monitoring of health-related physiological signals, even when exposed to aggressive solutions such as PBS, KOH, and glucose. A clear “filling–cross-linking” mechanism is revealed, involving the filling of the void spaces within polymer chains followed by the cross-linking of polymer side chains to enhance the density of the hybrid layer. Adjusting porosity and functional group density ensures complete Al2O3 infiltration into the polymer. The cross-linking increases from 12.31% to 73.79% compared to the UV-curing process alone due to the presence of Al2O3, further enhancing the density of the hybrid layer and its barrier properties. The proposed strategy in our work shows great potential for providing highly reliable encapsulation for wearable electronics.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Xiaobo Ding,Hailong Hu,Tailiang Guo,Fushan Li
InP quantum dots have received intensive attention due to their tunable emission wavelengths, narrow bandwidths, and high color purity. Nevertheless, InP quantum dots exhibit notable instability in a complex environment due to their highly oxidizable properties. In this study, we present a strategy for synthesizing InP@Al2O3 nanocomposites that have InP quantum dots evenly embedded in a hybrid substrate containing Al2O3 and coupling-interconnection layers of Si and Al. In addition, we used high-power UV irradiation to repair the defects generated during the synthesis process, leading to photoluminescence (PL) intensity increase of more than 10 times. InP@Al2O3 nanocomposites have demonstrated up to 9 h of laser stability, 30 days of water stability and acid stability and 20 days of alkali stability. It has far exceeded that of InP quantum dots and commercially available phosphors. Distal-type light-emitting diodes (LEDs) with stable and standard white emission can be realized by combining red and green InP@Al2O3 nanocomposites with blue LED chips.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2019
·Vol. 19
·期 6
·3471-3478
·
IF 1.093
Wang Feng,Ge Hong-Hua,Wu Kai,Wang Le-Tian,Wan Chuan,Sha Jun-Yi,Zhao Yu-Zeng
The effects of Al2O3 nanoparticles on the precipitation behavior of CaCO3 and on the anti-scale performance of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) in CaCO3 growth solution were studied by means of solution analysis, gravimetric
methods, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The results illustrate that Al2O3 nanoparticles had little effect on the concentration of calcium ions in the test solution without PBTCA, but significantly changed the
form and morphology of calcium carbonate crystals, which were transformed from calcite to aragonite. As a commonly used and effective scale inhibitor, PBTCA showed good Ca2+ retention ability in the test solution, distorting the calcite crystal lattice and promoting the formation
of vaterite. When Al2O3 nanoparticles co-existed with PBTCA in the test solution, calcium carbonate was more likely to precipitate, and the Ca2+ retention ability of PBTCA reduced. A newly designed gravimetric method was used to evaluate the scale inhibition
performance of Al2O3 nanoparticles on the heat exchange surface. When the concentration of Al2O3 nanoparticles reached 1 g/L, the surface scale inhibition efficiency of Al2O3 nanoparticles exceeded 80%.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Hang Qin,Wenming Guo,Xin Huang,Pengzhao Gao,Hanning Xiao
α-Al 2 O 3 nanoparticles with a particle size of ~10 nm were synthesized from aluminum alkoxide precursor chelated by oxalic acid at 500 °C and added to boehmite sol as phase transition seeds (PTS) in low temperature preparation of α-Al 2 O 3 ultrafiltration (UF) membrane. With the PTS doping of 2.5 wt%, a single phase α-Al 2 O 3 membrane with small pore size of 7.2 nm was prepared at 950 °C. After long-term static and dynamic corrosion tests, the as-prepared α-Al 2 O 3 UF membrane was found to no significant degradation in performance, displaying a stable MWCO and water permeability of 15 kDa and 85 L/(m 2 h bar) respectively. In the decolorization of vinegar fermentation wastewater, the COD removal was 63% whereas the color removal could reach 98%. Furthermore, the contaminated membrane could be reused many times after cleaning, confirming the excellent durability and practicality of α-Al 2 O 3 UF membrane in wastewater treatment .
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 45
·e202203339
·
IF 2.307
Junjie Zhang,Zhourong Xiao,Li Wang,Xiangwen Zhang,Guozhu Li
Graphical The key role of Ni valence state on the catalytic SMR performance of Ni/Al 2 O 3 is reported. Ni 0 /Ni 2+ ratio on Ni/Al 2 O 3 is individually regulated by changing the reduction temperature while maintaining the states of nickel particles and support. A deep understanding is gained on how the Ni valence state of Ni/Al 2 O 3 affects the catalytic SMR performance. Steam methane reforming (SMR) is the most mature technology for hydrogen production in industry, and alumina supported nickel (Ni/Al 2 O 3 ) is the most widely used catalyst. Herein, the key role of Ni valence state on the catalytic SMR performance of Ni/Al 2 O 3 is reported. The ratio of Ni 0 /Ni 2+ on Ni/Al 2 O 3 is individually and effectively tuned by changing the reduction temperature after wet impregnation. Catalytic performance of Ni/Al 2 O 3 is greatly dependent on the surface concentration of Ni 0 and Ni 2+ . The catalyst reduced at 675 °C possesses balanced Ni 0 and Ni 2+ sites and exhibits superior catalytic performance, on which 60 % of methane is stably converted at 600 °C. CH 4 -TPD and CO-TPD profiles demonstrate that appropriate Ni 0 /Ni 2+ ratio can promote the adsorption of CH 4 and inhibit the moderate-strength adsorption of CO, which leads to increased SMR activity and selectivity.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）