JOURNAL OF SOLID STATE CHEMISTRY
·
2015
·
IF 2.133
Tianfu Zhang,Zhen Wang,Guoping Li,Yunjun Luo
A bottom-up approach combining soft template self-assembly with sol–gel process, was adopted to prepare the assembled Al/Fe 2 O 3 nanoenergetic materials, assembly-Al/Fe 2 O 3 sample. The other two unassembled Al/Fe 2 O 3 a nanoenergetic materials, sol–gel–Al/Fe 2 O 3 sample and mixing-Al/Fe 2 O 3 sample, were prepared by sol–gel method and physical mixing method respectively. The assembly process within the preparation of the assembly-Al/Fe 2 O 3 sample was analyzed through the changes in the average hydrodynamic diameters of the particles and the micelles in solution. SEM, EDS and TEM tests were performed to demonstrate a significant improvement regarding to dispersity and arrangements of the Al and Fe 2 O 3 particles in the assembled samples, compared to that of the unassembled Al/Fe 2 O 3 samples. DSC test was employed to characterize the reactivity of the samples. The heat release of the assembled Al/Fe 2 O 3 sample was 2088 J/g, about 400 and 990 J/g more than that of the sol–gel–Al/Fe 2 O 3 sample and mixing-Al/Fe 2 O 3 sample, respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Liang Yu,Lv Shen,Hongzhe Zhong,Ru Zhou,Min Hao,Juncheng Jiang
Polypropylene (PP) flammability poses great fire risks for its application. A metal-organic framework (MOF), NH 2 -MIL-53(Al), was synthesized and subsequently integrated into PP, the flame-retardant efficacy in conjunction with piperazine pyrophosphate (PAPP) and melamine cyanurate (MCA) was additionally examined. When the total mass fraction of the additives was 25 %, the limiting oxygen index (LOI) of PP composite reached 31.1 %, it also passed the UL-94 test with a V-0 rating. The peak heat release rate (pHRR) and the total heat release rate (THR) was reduced by 88.55 % and 79.75 %, respectively, compared with the pure PP. The char residual char percentage increased to 8.02 %. The Tensile Strength reached 30.1 MPa. The results indicate that adding NH 2 -MIL-53(Al) significantly enhanced the flame retardancy and thermal stability of PP composites, without significantly affecting their mechanical properties, which offers a novel potential direction for the advancement of polymer flame retardants (FRs).
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2019
·
IF 4.888
Yiwen Jiang,Ling Zhang,Yiquan Xie,Shichao Han,Qiuyan Zhu,Xiangju Meng,Feng-Shou Xiao
A series of zeolite-supported Pt nanoparticles (Pt/NaZSM-5) have been prepared by adjusting Si/Al ratio of NaZSM-5 zeolite from 60 to pure silica. Catalytic tests in propene oxidation as an important model reaction for removal of hydrocarbons emitted from automobiles during cold-start, show that the catalytic activities significantly increase with Si/Al ratios of NaZSM-5 zeolite in these Pt/NaZSM-5 catalysts. As a typical example, Silicalite-1 supported Pt nanoparticles exhibits the highest activity, giving the 50% conversion temperature (T 50 ) and 90% conversion temperature (T 90 ) at 112 °C and 118 °C, respectively. Characterizations of these catalysts with multiple techniques show that the enhanced catalytic activities are strongly related to the zeolite Si/Al ratios of the catalysts, where an increase of zeolite Si/Al ratio is favorable for the adsorption of propene, promoting the propene oxidation. This feature might offer a good opportunity to design and prepare highly efficient heterogeneous catalysts for removal of light olefins in the future.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Xinhua Li,Xin Wen,Huanhuan Zhao,Zongqing Ma,Liming Yu,Chong Li,Chenxi Liu,Qianying Guo,Yongchang Liu
The microstructure and phase evolution in Nb-Al system during MA are systemically studied. The existence of Nb-Al amorphous layer surrounding Nb nano-grains after short-time ball milling was confirmed by the HRTEM observation as well as the crystallization behavior in the annealing experiment. It was also found that after short time milling, only very little Al can enter the crystal lattice of Nb and substitute for Nb, whereas most of Al mainly concentrate in this amorphous layer surrounding Nb nano-grains. What's more, interface thermodynamic analysis and calculation were employed to investigate the phase formation and evolution of this amorphous layer in Nb-Al binary system during MA process. Accordingly, positive driving force (≡-ΔG) definitely exists for the formation of the amorphous layer {NbAl} surrounding Nb nano-grains. Thus, these amorphous layers can form and exist stably in the short-time milled Nb-Al system. With the milling time prolonging, this amorphous layer becomes unstable and can crystallize into Nb(Al) ss solid solution when its thickness increases beyond a critical thickness. The critical thickness of this amorphous layer is also predicted by the interface thermodynamics calculation and the corresponding calculated value (approximately 1.9 nm) is consistent with the observed thickness (about 2.2 nm) by the HRTEM within the error range. More importantly, the solubility of Al in the lattice of Nb can be significantly increased resulting from the crystallization of this amorphous layer {NbAl}. Our work provides a new and rational perspective to well understand the complicated microstructure and phase evolution in various nano-sized systems during MA process.
研究领域:
材料科学
·
物理冶金学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2016
·Vol. 91
·期 11
·2842-2851
·
IF 2.738
Dingsheng Chen,Chaoping Cen,Jinxi Feng,Chunyang Yao,Waiqing Li,Shuanghong Tian,Ya Xiong
BACKGROUND It is of great interest to use pillared clay (PILC) as a cheap support for a selective catalytic reduction (SCR) catalyst. Al-Cr pillared clay (AlCr-PILC) has high thermal stability due to the introduction of polycations of Al. As a support, AlCr-PILC may show a co-catalytic effect in SCR processes because chromium oxide itself is an active SCR catalyst. The aim of this work is to investigate the potential of AlCr-PILC as a new low temperature SCR catalyst support. RESULTS A series of AlCr-PILC with Al:Cr molar ratio varying from 0:4 to 4:0 were successfully synthesized to support manganese and cerium active phase. MnCe/AlCr(2:2)-PILC exhibited the highest NO x conversion close to 100% at 200–300 °C, and more than 90% N 2 selectively over a wide temperature window of 140–300 °C. The catalytic activity of MnCe/AlCr-PILC in terms of both NO x conversion and N 2 selectivity is much higher than those of MnCe/Al-PILC, MnCe/Cr-PILC, AlCr-PILC, and the simple mixed MnCeAlCr, indicating the co-catalytic effect of AlCr-PILC support. CONCLUSION AlCr-PILC is a very promising low-temperature SCR catalyst support. The XRD, XPS, and H 2 -TPR measurements prove that the co-catalytic effect of AlCr-PILC occurred via the strong interaction between MnCe and the AlCr-PILC support. © 2016 Society of Chemical Industry
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 75
·47539-47546
·
IF 3.108
Song Zhang,Chao Xu,Guoqing Zhai,Mingliang Zhao,Mo Xian,Yuxiang Jia,Zongjiang Yu,Fusheng Liu,Fangfang Jian,Weizhi Sun
A new type of bimetallic palladium and aluminum incorporated mobile crystalline materials (Pd–Al-MCM-41) as bifunctional catalysts has been hydrothermally synthesized. Characterization shows that these molecular materials exhibit an ordered mesoporous structure, high surface area and a good dispersion of palladium in the frame. The catalytic activity of the Pd–Al-MCM-41 for the dimerization–hydrogenation reaction system of β-pinene in one pot has been systematically studied. Pd0.5–Al30-MCM-41 (SiO2/Al2O3 = 30, 0.5 wt% palladium content) was found to be the best catalyst which gave a dimer yield of up to 64.7%. It is worth noting that palladium shows a good synergic catalytic effect with aluminum in the dimerization reaction and enhances the dimerization yield. Furthermore, the bifunctional catalyst displayed a good activity over 4 runs.
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 HYDROGEN ENERGY
·
2024
·
IF 8.1
Wenchen Ren,Huanxi Wang,Qianlin Zhang,Mengchi Chen,Zhongrui Li,Huan Guo,Jing Bai,Xiaomin Dai,Santosh Kumar Verma,Yunhua Xu
In this paper, petal sheet layered Co-Al bimetallic hydroxides were prepared using the hydrothermal method using methanol as a solvent. Pt/Co-Al-O catalysts were produced after the impregnation method and H 2 reduction. This catalyst was applied to the dehydrogenation reaction process of methylcyclohexane to toluene. A fixed-bed reaction device carried out comparative tests of this series of catalysts, and the effect of Co addition on the performance of Pt/Co-Al-O catalysts was investigated in detail. Among them, the Pt/Co 3 -Al 1 -O catalyst showed the best performance with high toluene selectivity throughout the dehydrogenation process. The MCH conversion started to be greater than 90% at 330 °C, and the hydrogenolysis rate was 262.7 mmol/g Pt /min. The conversion gradually increased with the reaction temperature, and the conversion could reach 99.5% at 410 °C. The appropriate introduction of Co element can reduce the excessive strong acidic sites of Al 2 O 3 itself and retain a certain number of weak acidic sites, while the bimetallic hydroxide carrier improves the dispersibility of the active component, reduces its particle size, and forms a certain strong interaction between the carrier and Pt. The final conversion of the catalyst decreased by about 2% in the 100 h stability test at 380 °C, which indicated that the Pt/Co 3 –Al 1 –O catalyst had strong coking resistance and good stability. These results indicate that the Pt/Co–Al–O series catalysts have potential industrial applications in hydrogen energy utilization.
研究领域:
催化化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yan Zhao,Pengjun Zhao,Qing Zhao,Donglin He,Wenwen Kong,Bing Wu,Aimin Chang
Herein, Mg–Al–Si–Ba–O-based glass ceramics were studied as potential candidates to protect Mn–Co–Ni–O-based negative temperature coefficient (NTC) thermistors at high temperatures such as 900 °C. The ceramics were prepared in three glass formulations (1#: 15MgO–15Al 2 O 3 -44.7SiO 2 –25BaO, 2#: 17MgO–17Al 2 O 3 –41SiO 2 –25BaO and 3#: 17MgO–17Al 2 O 3 –41SiO 2 –20BaO–5Y 2 O 3 (in mol%)) and their glass-transition temperatures ( T g ) were determined using the differential scanning calorimetry (DSC) method. Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the parent glasses and glass-ceramic coatings. The sealing effects of the glass ceramics were examined by conducting an insulation test. The glass-ceramic sealing structures were subjected to 1000 thermal shock cycles at temperatures varying from room temperature to 900 °C. Notably, the sealing structure of glass-ceramic coating 1# was compact at a T g of 760.9 °C. The glass-ceramic coatings effectively maintained the NTC properties of the sensitive ceramics in all three formulations. Interestingly, the glass-ceramic coating 3# containing Y 2 O 3 demonstrated an increase in electrical resistance. Both the NTC thermistors coated with 1# and 2# glass formulations successfully passed 1000 thermal shock cycles without visible failures, and their resistance change ratios were well below the requisite 20%.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2024
·
IF 7.4
Zebang He,Zhong Wu,Zhiming Gao,Zhenbo Qin,Juntao Yuan,Yuan Gao,Yaorong Feng,Anqing Fu,Chun Wang,Wenbin Hu
A Ni-Al-Cu coating was prepared on NAB alloy through electroplating and heat treatment, and the erosion-corrosion behaviors were investigated. The results demonstrated that Ni-Al-Cu coating exhibited higher erosion resistance compared to NAB alloy, with an average reduction of 63 % in material removal rate (MRR). It was revealed that deformation and cracks were observed in NAB, with loss of hard κ and β phases alongside deformation of ductile α phase. Meanwhile, Ni-Al-Cu coating experienced fatigue delamination and grain disintegration due to alternating stress. Taguchi design method showed that increasing flow velocity and sand concentration could enhance the intensity of gravel impact, while changes in the erosion angle affected gravel impact modes and energy transfer, thereby impacting corrosion performance. Additionally, empirical equations for the material removal rate were derived through regression analysis, which became possible to predict the MRR under different influencing factors and assess the erosion-corrosion resistance of materials.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2019
·
IF 2.291
Xiangping Li,Han Yin,Jianguang Zhang,Juping Liu,Guanyi Chen
Template removing approaches can significantly impact the physiochemical properties of mesoporous molecular sieve materials. In order to better understand the relationship between template removing approaches and the properties of Ni/Al-SBA-15, four kinds of template removing approaches were introduced to remove the organic template from Al-SBA-15, respectively. The structural characteristics of these materials were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray fluorescence (XRF), powder X-ray diffraction (XRD), N 2 -sorption, Fourier transform infrared spectra (FT-IR), infrared spectra of pyridine adsorption (Py-FTIR), magic angle spinning-nuclear magnetic resonance (MAS-NMR), X-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC-MS). Ni/Al-SBA-15 of which the organic template was removed by two-step calcination method had the maximum specific surface area (619 m 2 /g). In contrast, Ni/Al-SBA-15 of which the organic template was removed using solvent extraction approaches had the lowest specific surface area (555 m 2 /g). The mesopore diameter of Ni/Al-SBA-15, using electric heating digestion method to remove the template, was significantly increased and the wall thickness was significantly decreased to 11.62 nm in comparison with the other samples. The selectivity of products during the process of eugenol hydrodeoxygenation was investigated. High hydrocarbons were obtained during catalytic hydrodeoxygenation over Ni/Al-SBA-15 of which the organic template was removed by using solvent extraction approaches. Compared with direct calcination process, two-step calcination was more effective in removing template and the corresponding catalyst was much more suitable for the hydrodeoxygenation process.
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
COMPOSITES SCIENCE AND TECHNOLOGY
·
2016
·
IF 3.897
Yu Zhao,Nana Li,Shengji Xia
Zn–Al layered double hydroxides (LDH) modified polyamide (PA) nanofiltration (NF) membranes were successfully fabricated by interfacial polymerization of 1,3-Phenylene diamine (MPD) and 1,3,5-Benzenetricarbonyl trichloride (TMC) monomers . Compared to raw PA membranes, the LDH incorporated membranes showed denser PA layers with more leaf-like folds, rather than ridges and valleys, according to images from field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM). Higher hydrophilicity (with the contact angle decreased from 70.33° to 55.66°) and water permeability (with pure water flux enhanced from 6.76 to 9.48 L/m 2 h, measuring approximately 40.2% improvement) were achieved by PA membranes embedded with Zn–Al LDH nanoparticles . The rejection ability of different membranes was evaluated using Aldrich-humic acid (HA) and water from the Huangpu River; the results indicated that PA/LDH membranes exhibited a higher removal efficiency of natural organic matter (NOM). Excitation–emission matrix (EEM) fluorescence spectroscopy was also used in analysing raw natural water and permeate to investigate the removal mechanism toward different types of organic matters; better antifouling properties were observed for modified PA membranes.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Zhi-Rong Li,Jing Liu,Jing-Yi Sun,Zhi-Yi Hu,Wan-Ying Li,Ting-Ting Shen,Mei-Tong Wei,Zhi-Wen Yin,Si-Ming Wu,Gustaaf Van Tendeloo,Yu Li,Bao-Lian Su
The Ni/Al layered double oxide (Ni/Al-LDO) is a promising photocatalyst because of the high surface area and abundant active sites. However, the application of Ni/Al-LDO for photocatalytic hydrogen evolution is hindered by the unclarity of the optimized microstructure and limited light absorption. In this work we report the structural evolution from Ni/Al layered double hydroxides (Ni/Al-LDH) to Ni/Al-LDO, which is able to achieve a precise regulation of the layered structure with abundant acid sites for photocatalysis. Further, CdS quantum dots (QDs) are in-situ grown on the sheet-like Ni/Al-LDO to obtain a close contact 0D/2D CdS-Ni/Al-LDO heterojunction. CdS-Ni/Al-LDO exhibits a hydrogen evolution efficiency of 20.3 mmol/g/h and an apparent quantum yield (AQY) of 22.2 % at a wavelength of 450 nm. The superior performance is attributed to the synergistic effects of abundant Lewis and Brønsted acid sites of Ni/Al-LDO, the layered structure with a high specific surface area and the heterojunction between Ni/Al-LDO and the CdS QDs.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）