Catalysts
·
2024
·Vol. 14
·期 11
·827
·
IF 3.8
Yumeng Song,Ping Chen,Hui Lou,Xiaoming Zheng,Xiangen Song
In this work, the highly efficient hydrogenation of guaiacol catalyzed by ruthenium supported on Al2O3-TiO2(Ru/Al2Ti1) at very mild conditions was carried out. At temperatures as low as 25 °C and 2 MPa H2, about 60% of guaiacol could be converted to 2-methoxycyclohexanol (MCH) with a selectivity as high as 94% on the Ru/Al2Ti1catalyst with an appropriate hydrogen pressure. At temperatures above 50 °C, almost all of the guaiacol could be converted with the catalyst of Ru/Al2Ti1, mainly into hydrogenated products such as MCH. The surprisingly efficient hydrogenation of guaiacol at low temperatures was most likely due to the ability of Ru particles loaded on the specific complex metal oxide carriers, particularly the reduction of the edge effect of Ru, to activate phenyl and hydrogen and reduce the competition of the dimethoxy process. These findings about the high activity of the Ru/Al2Ti1catalyst at nearly room temperature may be helpful to upgrading the industrial process of the pyrolysis bio-oils.
研究领域:
催化化学
·
可再生能源
·
工业化学
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产品关联
DOI
高影响因子
Processes
·
2022
·Vol. 10
·期 10
·1946
·
IF 3.352
Hong Shen,Zijun Tang,Xiang Xiao,Haiwen Wu,Hang Zhou,Ping Fang,Dingfang Zhu,Jianhua Ge
In this study, Mn-Ce/Al2O3/TiO2catalyst prepared by impregnation method was used for synergistic O3oxidation NO. The catalyst prepared by impregnating Al2O3/TiO2at a Mn:Ce molar ratio of 4:1 showed the best catalytic activity. The catalyst performance showed that when the molar ratio of Mn:Ce was 4:1 and the volume ratio of O3:NO was 1:4, the removal rate of NO could reach 63%, which could increase the removal rate by 40% compared with that of NO oxidized by O3alone. BET, XRD, and TEM characterization results showed that when the molar ratio of Mn:Ce was 4:1, the catalyst specific surface area, and pore capacity were the largest. A large amount of MnOx and CeOx were distributed on the catalyst surface. The XPS analysis showed that the oxidation-reduction and oxygen vacancy of Mn (IV)/Mn (III)/Mn (II) and Ce (IV)/Ce (III), had a synergistic effect on the decomposition of O3into reactive oxygen species(O*), thus improving the catalytic capacity of Mn-Ce/Al2O3/TiO2catalyst for O3. The O2-TPD analysis showed that the oxygen vacancies and oxygen species in the catalyst could be used as the active point of decomposition of O3into O*. The experimental results show that the prepared catalyst can significantly improve the efficiency of ozone oxidation of NO and reduce the amount of ozone. The catalyst can be applied to ozone oxidation denitrification technology.
研究领域:
环境科学
·
催化化学
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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
·
纺织工程
·
表面改性技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Chengyin Lin,Yongyuan Deng,Yuankai Lin,Jun Li,Junling Tu,Riyang Shu
Hydrodeoxygenation (HDO) represents a highly efficient refining pathway to convert lignin-derived phenolic compounds for the production of hydrocarbon fuels, and the selection of a suitable catalyst is pivotal for a high reaction efficiency. In this study, we introduce a novel highly dispersed Pt/Al2O3–TiO2 composite catalyst that is prepared via a photochemical reduction method and employ it for the HDO of lignin-derived phenolic compounds. The catalyst demonstrates a good HDO performance, achieving complete conversion of guaiacol at 260 °C with cyclohexane selectivity of 99.9%. Catalyst characterization results reveal that the Pt/Al2O3–TiO2 catalyst exhibits a high Pt metal dispersion. Besides, the composite support synergistically combines the properties of Al2O3 and TiO2 components, resulting in a high specific surface area, moderate acidity, and abundant oxygen vacancy. These factors facilitate the provision of numerous active metal sites and acid sites those are essential for the HDO reaction. Moreover, the Pt/Al2O3–TiO2 catalyst also shows a high activity on the HDO of various other phenolic compounds. When applied to the upgrading of lignin oil, the catalyst significantly increases the hydrocarbon content from 18.9% to 92.2%, concurrently reducing the oxygen content and substantially increasing the hydrogen content of the lignin oil. The calorific value is significantly enhanced, underscoring the potential of the Pt/Al2O3–TiO2 composite catalyst to upgrade lignin-derived phenolic compounds into high-quality hydrocarbon liquid fuels.
研究领域:
催化化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Ling Ding,Ting Xiong,Zhibo Zhao,Jun Liao,Yong Zhang
In this study, Al 2 O 3 -TiO 2 nanocomposite was in-situ fabricated using cross-linking-freeze-drying technology for the separation of U(VI). Al 2 O 3 -TiO 2 nanocomposite exhibited an excellent removal property for U(VI) with a removal efficiency of 97.5% and a maximum adsorption capacity of 586.7 mg g −1 , which exceeded those of other TiO 2 -based adsorption materials. After five cycles, the removal percentage for U(VI) on Al 2 O 3 -TiO 2 nanocomposite still maintained more than 90.0%. The study of isotherm and kinetic demonstrated that the removal behavior of Al 2 O 3 -TiO 2 nanocomposite for U(VI) was monolayer chemisorption . Furthermore, the results of pH zpc , BET, SEM, FTIR and XPS analysis manifested that the interactions between Al 2 O 3 -TiO 2 nanocomposite and U(VI) included electrostatic interaction, surface complexation, oxygen vacancy chemistry and redox reactions . In one word, Al 2 O 3 -TiO 2 nanocomposite was a potential candidate as adsorbent in U(VI)-bearing wastewater remediation owing to its simple preparation method and the excellent removal properties.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 71
·40989-40995
·
IF 2.936
Ruifeng Wang,Lungang Chen,Xinghua Zhang,Qi Zhang,Yuping Li,Chenguang Wang,Longlong Ma
Novel catalytic material with high catalytic activity and hydrothermal stability plays a key role in the efficient conversion of levulinic acid (LA) to γ-valerolactone (GVL) in water. In this study, mixed oxides Al2O3–TiO2, Al2O3–MoO3 and Al2O3–Co3O4 were synthesized by co-precipitation using aqueous solution of NaOH as precipitant. Ru catalysts supported on mixed oxides were prepared by impregnation method and their catalytic performances were tested in the hydrogenation of LA to GVL on a fixed bed reactor. The physicochemical properties of the catalysts were characterized by XRD, H2-TPR, NH3-TPD, and BET techniques. The TiO2 component significantly affected the acidity of the catalyst, and thus its catalytic activity for the GVL yield was affected. The desired product GVL with a yield of about 97% was obtained over the Ru/Al2O3–TiO2 catalyst under mild conditions (WHSV = 1.8 h−1, T = 80 °C). Moreover, the catalyst Ru/Al2O3–TiO2 exhibited excellent thermal stability in the test period of time.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOM
·
2022
·Vol. 75
·期 6
·1982-1992
·
IF 2.597
Qiu Yuchao,Shi Junjie,Hou Changle,Dong Jingjing,Zhai Yumo,Li Kaixuan,Yan Sen,Yu Kai,Li Jianzhong,Liu Changsheng
The spinel and pseudobrookite type ceramic materials have been widely used in different industries including ceramics, refractory and metallurgy. Therefore, their physicochemical properties are important for the development of related processes. In this regard, it is important to understand the formation principles of the spinel and pseudobrookite solid solutions. In the present work, the equilibrium phase relations for the MgO-Al 2 O 3 -TiO 2 system at 1700°C in air were experimentally determined by high-temperature equilibration-quenching technique followed by XRD and SEM–EDS analyses. The pseudobrookite solid solution was found to be coexisting with spinel solid solution and rutile phase, respectively. The composition evolution and formation principles of the pseudobrookite and spinel solid solutions were further elucidated from the corresponding crystal structures and composition relations. Furthermore, great discrepancies were observed when the 1700°C isotherm from the present work was compared with the isotherm simulated by FactSage 8.1. The evolution of the solid solution existing area was intuitively presented with reference to the experimental data from the literature. The results from present work are important for the development of spinel and pseudobrookite solid solution ceramics as well as the optimization of the thermodynamic database for oxide systems.
研究领域:
材料科学
·
陶瓷工程
·
热力学
✓ 已验证
DOI
高影响因子
Materials Today Nano
·
2025
·
IF 8.2
Pingan Chen,Sizeng Hong,Xiangcheng Li,Yingli Zhu,Fu Chen,Mengke Qiao
Carbon nanofibers can be widely used in the field of electromagnetic wave absorption due to corrosion resistance, low density and good chemical stability. Here, we report a strategy to achieve strong microwave absorption capability by adjusting the crystallinity of carbon nanofibers containing Al 2 O 3 and TiO 2 . TiO 2 with Ti 3 C 2 T x MXene as a precursor decreases the crystallization temperature of Al 2 O 3 from 1400 °C to 800 °C in the carbon nanofibers. The diameter distribution of carbon nanofibers is uniform, though the surface of carbon nanofibers is getting rough with Ti 3 C 2 T x content increasing. The minimum reflection loss of carbon nanofibers is -55.78 dB at a thickness of 4.32 mm; the effective absorption bandwidth reaches 5.41 GHz (12.59-18 GHz) at a thickness of 1.67 mm, almost covering the Ku band. The excellent microwave absorption performance can be attributed to the synergistic effect of the non-crystalline carbon matrix and crystalline Al 2 O 3 /TiO 2 , in which the former improves impedance matching with free space, while the latter enhances the attenuation capability to the electromagnetic wave.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2018
·Vol. 7
·期 2
·152-159
·
IF 1.605
Wu Jia-Min,Xiao Huan,Liu Meng-Yue,Chen Ying,Ma Yi-Xin,Cheng Li-Jin,Shi Yu-Sheng
In this paper, in-situ coagulation of 0.9Al 2 O 3 –0.1TiO 2 suspension and microwave dielectric properties of 0.9Al 2 O 3 –0.1TiO 2 ceramics prepared by a novel direct coagulation casting via high valence counter ions (DCC-HVCI) method were proposed. The 0.9Al 2 O 3 –0.1TiO 2 suspension could be coagulated via controlled release of calcium ions from calcium iodate at an elevated temperature. The influence of tri-ammonium citrate (TAC) content, solid loading, and calcium iodate content on the rheological properties of the suspension was investigated. In addition, the influence of coagulation temperature on coagulation time and properties of green bodies was also studied. It was found that the stable 0.9Al 2 O 3 –0.1TiO 2 suspension could be successfully prepared by adding 0.3 wt% TAC and adjusting pH value to 10–12 at room temperature. 0.9Al 2 O 3 –0.1TiO 2 green bodies with uniform microstructures were coagulated by adding 8.0 g/L calcium iodate after treating at 70 °C for 1 h. 0.9Al 2 O 3 –0.1TiO 2 ceramics, sintered at 1500 for 4 h and annealed at 1100°C for 5 h, showed °Cuniform microstructures with density of 3.62±0.02 g/cm 3 . The microwave dielectric properties of 0.9Al 2 O 3 –0.1TiO 2 ceramics prepared by DCC-HVCI method were: ε r = 11.26±0.06, Q × f = 11569±629 GHz, τ
f
= 0.93±0.60 ppm/°C. The DCC-HVCI method is a novel and promising route without binder removal process to prepare complex-shaped microwave dielectric ceramics with uniform microstructures and good microwave dielectric properties.
研究领域:
材料科学
·
陶瓷学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2026
·Vol. 109
·期 8
·e71094
·
IF 4.2
Weijia Guo,Bowen Yin,Hui Zhang,Xingchen Zhang,Chongyang Zhang,Qingshuo Zhang,Zhenxing Yue
The development of high-power millimeter-wave technology introduces new requirements on microwave dielectric ceramics. In addition to lower dielectric loss, higher thermal conductivity is also needed to meet heat dissipation demands. Developing high-thermal-conductivity microwave dielectric ceramics with larger relative permittivity ( ε r ) would facilitate the miniaturization of high-power devices. Adding TiO 2 to the α-Al 2 O 3 matrix can adjust the temperature coefficient of resonant frequency ( τ f ) to near zero while increasing ε r , making it an effective approach to obtain high thermal conductivity and low-loss microwave dielectric ceramics. However, systematic defect analysis of the Al 2 O 3 –TiO 2 composition is still lacking. This work investigates the dielectric and thermal properties of the Al 2 O 3 –TiO 2 composition from a defect perspective. By combining low-frequency dielectric spectra with thermally stimulated depolarization current (TSDC) techniques, it was found that the solid solution of Al 3+ in the rutile TiO 2 phase suppresses the activity of defects such as oxygen vacancies. However, the introduction of Ti 4+ into the Al 2 O 3 phase introduces aluminum vacancies (
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DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2025
·
IF 6.1
Xiafeng Wan,Ximing Duan,Pengfei He,Shujun Hu,Lin Xue,Liliang Shao,Chuan Sun,Bo Zhang,Jiangbo Cheng,Xiubing Liang
This study investigates the influence of Al 2 O 3 -20wt%TiO 2 (AT) modification on the hot corrosion resistance of YSZ coating. The YSZ coating, YSZ-AT composite coating, and YSZ/AT double layer coating were prepared using plasma spraying. An innovative dynamic corrosion method was conducted by plasma spraying NaCl under a heat flux density of 3350 kW/m 2 for 60 s, and the peak surface temperatures during corrosion exceeded 1500 °C during corrosion The results revealed that the YSZ coating suffered structural damage due to molten salt infiltration after corrosion, exhibiting a mass increase of 2.14 mg/cm 2 . In contrast, the composite coating exhibited the most severe damage due to the depletion and spalling of the AT phase, with a significant mass loss of 18.46 mg/cm 2 . However, the YSZ/AT double layer coating retained its structural integrity, experiencing only a moderate mass loss of 6.6 mg/cm 2 . The dense AT top layer (initial porosity about 0.378 %) effectively prevented molten salt penetration and acted as a sacrificial coating, reacting with the molten salt to consume corrosive media, thus demonstrating the best hot corrosion resistance.
研究领域:
材料科学
·
腐蚀工程
·
热障涂层
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2026
·
IF 9.9
Yaofei Lin,Guangheng Wang,Xingxing Meng,Jiahuan Zhao,Hongju Wu,Wenying Zhou
Against the backdrop of the booming sophisticated electronics industry, polymer composites integrating superior dielectric permittivity ( ε ), low loss (tan δ ) and excellent breakdown strength ( E b ) have become a persistent pursuit in the research community. To simultaneously bolster the ε and E b in alumina (Al)/polyvinylidene fluoride (PVDF), in this study the neat Al particles were first surface-oxidized to thicken the alumina (Al 2 O 3 ) thickness and then encapsulated with a titanium dioxide (TiO 2 ) layer, followed by an investigation into the dielectric properties of the resulting Al@Al 2 O 3 @TiO 2 /PVDF composites. The results indicate that the Al@Al 2 O 3 @TiO 2 /PVDF exhibits a higher ε and E b but lower tan δ relative to pristine Al/PVDF. The elevated ε stems from the synergistic regulation of high-frequency fast intra-particle and low-frequency slow inter-particle polarizations in Al@Al 2 O 3 @TiO 2 /PVDF. The Al 2 O 3 @TiO 2 double-shell not only prevents direct contact between conductive Al but also induces deep traps immobilizing charges and lifts the energy barrier for captured charges de-trapping, thus restraining the tan δ and leakage current. Moreover, the double-shell effectively strengthens interfacial interactions and alleviates strong dielectric mismatch between the two components, leading to much reduced electric tree growth and improved E b . Theoretical simulation further reveals a profound understanding of the inherent multiple polarization mechanisms and the charge migration modulation induced by the double-shell structure. So, this work provides unique insights for realizing simultaneously high ε , superior E b and minimal tan δ via core@double-shell structure in percolating composites, which cannot be achieved in traditional composites, offering considerable application potential in power equipment and electric devices.
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产品关联
DOI
高影响因子
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