MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Xiao Guo,Haibo Wang,Rui Tian,Haojiang Yin,Yunfeng Qiu,Feng Wang
Hydrophobic α-Al 2 O 3 ceramic membrane (HCM) offers excellent mechanical properties , corrosion resistance , and high-temperature resistance. Application of HCM in the membrane distillation (MD) process could expand the application scope of MD equipment and greatly lengthen the replacement cycle of the membrane. Here a prediction model of the contact angle of HCM was constructed by physical-chemical combined modification method, orthogonal method, and stepwise linear regression method to optimize the preparation process of HCM. The surface morphology , contact angle, and surface functional groups of HCM were characterized. In this work, we polished the surface of the α-Al 2 O 3 ceramic membrane with 400 mesh sandpaper to copy the optimal morphology and found that the effect of grafting time on the contact angle of HCM could be abandoned. The optimal levels of drying temperature, drying time, and grafting solution concentration were 250 °C, 65.5 min, and 0.019 mol/L, respectively. The contact angle of HCM was 145.3° corresponding to the optimal preparation process. The significance of the prediction model of the contact angle of HCM was better than 0.05, and all of the prediction errors were less than 5%. This work has an important guiding value for exploiting the optimum hydrophobic property of HCM.
研究领域:
材料科学
·
化学工程
✓ 已验证
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
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2020
·
IF 3.465
Yu Li,Luchao Wu,Yun Wang,Peng Ke,Jie Xu,Baohong Guan
Ozone decomposition into free radicals, which can be facilitated by enhancing electron transfer between ozone and catalyst, is an important segment in catalytic ozonation. We doped cerium uniformly on γ-Al 2 O 3 with an impregnation–calcination method to enhance electron transfer in catalytic ozonation of phenol in aqueous solution. The removal efficiency of phenol is raised from 39.7% by ozonation alone to 46.3% by catalytic ozonation with Ce/Al 2 O 3 in 50 min reaction. A higher Ce 3+ /Ce 4+ ratio in Ce/Al 2 O 3 witnesses a higher electron transfer rate in catalytic ozonation and thus a higher degradation efficiency of phenol, illustrating that the activity of Ce/Al 2 O 3 depends on the valence state of Ce. The electron transfer cycle is formed by the electron donation from Ce 3+ to ozone molecule and the electron acceptance of Ce 4+ from adjacent lattice oxygen. After getting the electron, the ozone molecule is decomposed to generate free radical of ·OH on the surface of Ce/Al 2 O 3 . The continuous flow experiments exhibit a stable and high catalytic activity of Ce/Al 2 O 3 for catalytic ozonation, implying the feasibility in practical application.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2016
·
IF 2.75
Yi Li,Muhammad Nadeem Amin,Xingmei Lu,Chunshan Li,Fuqiang Ren,Suojiang Zhang
The catalyst NiO/MgO–Al 2 O 3 was prepared by loading magnesium and nickel onto the surface of γ-Al 2 O 3 beads, respectively, and was adapted to in situ upgrade the high temperature pyrolysis vapor derived from coal pyrolysis. The catalyst synthesis process, and structural variation were characterized by the XRD, SEM, and physical adsorption analyzer. In order to examine the catalytic effect on the different nickel loading ratio in the catalysts, the solid–liquid–gas product distribution, variation of gas and components of coal tar were studied by simulated distillation, GC/MS, elemental analysis and so on. The results shows both the tar yield and the content of the light fraction in the tar can be increased by catalytic up grade. The catalyst has a strong ability to convert the heavy component and polycyclic aromatic hydrocarbons in the tar to lower molecular weight components.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Lu Lv,Min Zhao,Yanan Liu,Yufei He,Dianqing Li
Alumina (Al 2 O 3 ) is widely used in the chemical industry as the catalyst and support due to its high specific surface area, abundant pore size distribution and chemical stability. However, the occurrence of hydration in water environment, result in outstanding decrease in specific surface area and collapse of pore structure. In this work, dodecyl phosphoric acid (PA) is used to modify the surface of Al 2 O 3 to obtain a series of hydrophobic material (Al 2 O 3 -PA). Based on XPS and NMR analysis, PA is chemically bonded on Al 2 O 3 to form P O Al bond. Furthermore, BET and WCA results display that Al 2 O 3 -1PA exhibits excellent the hydrophobicity and hydrothermal stability while maintains the pore structure. Take it as the substrate to support the Pd nanoparticles , the as-prepared Pd/Al 2 O 3 -PA shows the superior catalytic performance in the hydrogenation of phenol and anthraquinone relative to Pd/Al 2 O 3 , indicating the accessibility of Pd sites after PA modification. Especially, the significantly enhanced stability is also obtained in four cycles for aqueous phenol hydrogenation. This can be ascribed that the PA modification inhibits the aggregation of Pd nanoparticles and the products adhesion in the reaction process. The extension of PA coatings to monolithic catalysts could expand their current capabilities in industrial applications and warrants ongoing investigation.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2023
·Vol. 20
·期 5
·2737-2746
·
IF 2.1
Zhaoping Hou,Xinhe Yang,Zihan Tian,Liangliang Liu
Porous Al 2 O 3 ceramic beads with a small-scale lamellar pore structure were prepared by the dripping-ice templating method. The densification behavior of lamellar walls and the attrition resistance of porous Al 2 O 3 beads were investigated. For the two-dimensional structural lamellar walls, the intrinsic pores shrunk, and the necking area grew during the sintering process, leading to the densification of lamellar walls and the shrinking of porous beads. In addition, the two-dimensional lamellar walls and three-dimensional Al 2 O 3 bulk are compared and possibilities of elaborating of the discrepancy in grain size and pore morphology are discussed. Attrition resistance was determined by a grinding test. The dominant attrition mechanism of porous Al 2 O 3 beads is abrasion. High sintering temperature led to a decrease in the attrition rate due to a wider necking area and denser pore walls.
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
International Journal of Applied Ceramic Technology
·
2023
·Vol. 21
·期 1
·427-437
·
IF 2.1
Yulong Wang,Zhoufu Wang,Xitang Wang,Hao Liu,Yan Ma,Pengcheng Jiang,Yunjie Dong,Jiwei Niu
Short carbon fiber is a promising candidate for reinforcing carbon-containing refractories at the macro scale due to its excellent high-temperature stability and mechanical properties. In this work, the microstructure evolution of short carbon fiber and the effect of its addition on the properties of Al 2 O 3 –C refractories are investigated. The results show that adding short carbon fiber could affect the distribution of in situ ceramic phases, combined with the cross-scale reinforcement effect, leading to high strength—the CMOR of short carbon fiber containing refractories could be 23.0% higher than the free ones, while the HMOR could be 22.0% higher. Furthermore, the results suggest that the short carbon fiber containing refractories treated at 1400°C possesses high resistance to the initiation of crack propagation, which could be attributed to the high bonding strength brought by carbon fiber. Noteworthy, adding short carbon fiber could improve thermal shock resistance. The short carbon fiber containing refractories treated at 1300°C could possess a higher residual strength ratio than free ones. For instance, the specimen containing 0.1 wt% short carbon fiber shows the highest residual strength ratio (87.7%).
研究领域:
材料科学
·
高温材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Hanhan Chen,Xiaobin Wang,Yi Liu,Tengfei Yang,Naitao Yang,Bo Meng,Xiaoyao Tan,Shaomin Liu
Despite many methods available to synthesize MOF membrane, the cost-effective synthesis with high reproducibility and scalability is still a challenge. We present here a homologous support-induced approach for the growth of ZIF membrane supported on the dual-layer ZnO–Al2O3 hollow fibers, which has the potential for applications at larger scales. The developed unique dual-layer hollow fibers consisting of a thin outer ZnO layer firmly attached onto an inner porous alumina substrate were realized through one-step co-extrusion/sintering technique. During the MOF membrane synthesis, ZnO can be used not only as the support, but also as the nucleation sites and growth centers for the ZIF-8 membrane formation. More importantly, ZnO can act as a transitional bridge to direct the membrane growth outward along the support and inward embedded into the support, which significantly improving the binding force between the support and MOF, thus bringing in the outstanding membrane stability. Permeation of single gas and separation of binary mixtures revealed that the prepared membranes were free of defects. The resultant ZIF-8 composite membrane exhibits good hydrogen separation performance and excellent reproducibility. This protocol can achieve an easy and large-scale synthesis. In addition to ZIF-8 membrane, ZIF-67 membrane was also successfully synthesized via this method, which may provide some general guidelines for the preparation of other MOF membranes.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Yubiao Li,Yu Liu,Xueqian Wang,Yixing Ma,Ping Ning,Langlang Wang,Xiang Li,Rui Cao
Activated alumina-based composite oxide support is a commonly used support in hydrodesulfurization (HDS) catalysts, which not only retains the performance advantages of each component in the composite oxide support, but also significantly improves the defects of a single activated alumina support, such as the strong metal-support force of interaction. In this study, NiO-Al 2 O 3 composite support was prepared by introducing NiO-modified Al 2 O 3 , and MoS 2 /NiO-Al 2 O 3 catalysts were prepared for the hydrodesulfurization of COS by liquid phase reduction method. In the COS hydrogenation reaction, the MoS 2 /NiO-Al 2 O 3 catalyst achieved complete conversion of COS at 220 °C and showed more than 99.9% H 2 S selectivity. In stability tests, the catalyst maintained a COS conversion of over 99% throughout the 23-h hydrogenation reaction. Various characterization results show that the NiO-Al 2 O 3 composite support prepared by introducing NiO-modified Al 2 O 3 weakens the metal-support interaction force between MoS 2 and NiO-Al 2 O 3 composite support, which is conducive to the synthesis of MoS 2 with multilayer and long wafer structures. And it can significantly increase the formation rate of MoS 2 to 87.9%, which greatly improves the active site content of the catalyst. Furthermore, the dual modulation of MoS 2 and Al 2 O 3 by NiO modulated the surface alkalinity of the catalysts and promoted the formation of a large number of active edge sites in the MoS 2 /NiO-Al 2 O 3 catalysts, which in turn significantly improved the HDS performance of the catalysts. In addition, EPR characterization combined with experiments showed that the sulfur vacancies are the active sites for catalytic COS hydrodesulfurization over MoS 2 -based catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xin Huang,Le-Tian Wang,Yan-Fang Song,Fang Ge,Yi Zhang,Xin-Jing Meng,Hong-Hua Ge,Yu-Zeng Zhao
The use of nanofluids as vehicle coolant can significantly improve the heat exchange efficiency, but it is necessary to understand its corrosiveness to metals before use. Corrosion behavior of aluminum alloy in simulated vehicle coolant (SVC), nano Al 2 O 3 coolant (SVC-Al 2 O 3 ), simulated coolant containing sodium dodecyl benzene sulfonate (SVC-SDBS) and nano Al 2 O 3 coolant containing SDBS (SVC-Al 2 O 3 -SDBS) was investigated by electrochemical impedance spectroscopy , polarization curve, weight loss analysis and surface analysis in this paper. The results showed that in the three media of SVC, SVC-SDBS and SVC-Al 2 O 3 -SDBS, the impedance modulus at the frequency of 10 mHz |Z| 0.01 , the charge transfer resistance R ct and the film resistance R f of aluminum alloy electrode increased with the immersion time. Compared with the three media, the aluminum alloy in SVC-Al 2 O 3 medium had the lowest |Z| 0.01 , R ct and R f , and had the highest corrosion current density, implying that Al 2 O 3 nanoparticles promoted the corrosion of aluminum alloy in SVC, and the corrosion products formed on the alloy surface were Al 2 O 3 , Al(OH) 3 , AlOOH, which were loose and not protective. The R f values of aluminum alloy electrode increased significantly with time in the media containing SDBS. The aluminum alloy exhibited the best corrosion resistance in the medium of SVC-SDBS and no obvious loose corrosion products but compact passivation film could be seen on the alloy surface. SDBS exhibited a good corrosion inhibition effect on aluminum alloy, which may be due to the adsorption of SDBS on the metal surface and the fact that SDBS promoted the formation of the passive film by preventing the transformation of alumina film to loose AlOOH layer. In the medium containing both SDBS and Al 2 O 3 nanoparticles, the corrosion inhibition effect of SDBS was weakened. This maybe due to the electrostatic attraction of positively charged Al 2 O 3 nanoparticles and negatively charged SDBS, which reduced the adsorption of SDBS on the metal surface, thereby weakening the protective effect of SDBS on the metal surface.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 19
·4133-4141
·
IF 5.686
Lina Zhang,Bangjie Zhang,Peng Xue,Jiwei Li,Zhun Zhang,Yanling Yang,Shuai Wang,Jingdong Lin,Honggang Liao,Yong Wang,Yali Yao,Shaolong Wan,Haifeng Xiong
Graphical Room temperature oxidation : Pretreatment methods affect the nature of the Pd species and the reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature. The steam treatment (H 2 O/Ar) increased the metal Pd dispersion, and generated more active hydroxyl groups, leading to the enhanced reactivity in formaldehyde oxidation. A Pd/Al 2 O 3 nanocatalyst was pretreated at 750 °C in air, Ar or H 2 O/Ar, respectively. The effect of these different pretreatments on the active species and reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature was investigated. The pretreatment was found to affect both the phase transformation of PdO to Pd metal and the Pd dispersion, leading to different catalytic performances. We found that the Pd/Al 2 O 3 nanocatalyst pretreated in both Ar and H 2 O/Ar show 60 % and 100 % formaldehyde conversion at 25 °C, respectively, while the catalyst pretreated in air is not active under the same condition. Pretreatments in both Ar and H 2 O/Ar were found to facilitate the formation of metallic Pd on Pd/Al 2 O 3 catalyst, confirmed by both experiments and calculation based on the function of the equilibrium oxygen pressure and temperature. We further found that the catalyst pretreated in H 2 O/Ar has higher Pd dispersion and more surface OH groups compared to that pretreated in Ar, leading to improved activity in formaldehyde oxidation.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2016
·
IF 4.312
Kun Jiang,Dong Sheng,Zihao Zhang,Jie Fu,Zhaoyin Hou,Xiuyang Lu
Mixed MgO–Al 2 O 3 (with different Mg/Al ratio) supported nickel catalysts were prepared via co-precipitation method and used for hydrogenation of levulinic acid to γ-valerolactone under mild condition. Characterization results indicated that mixed MgO–Al 2 O 3 supported Ni catalysts possessed bigger surface area than that of Ni/MgO and Ni/Al 2 O 3 , and Ni dispersed highly on the surface of mixed MgO–Al 2 O 3 support. It was found that mixed MgO–Al 2 O 3 supported Ni catalysts were more active and selective for the hydrogenation of levulinic acid to γ-valerolactone than that of Ni/MgO and Ni/Al 2 O 3 , and the best yield of γ-valerolactone at 160 °C, 1 h and 3 MPa H 2 reached 99.7% over Ni/MgAlO 2.5 , and Ni/Mg 2 Al 2 O 5 could be recycled without obvious loss of its initial activity.
研究领域:
化学工程
·
催化化学
✓ 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）