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
Nanomaterials
·
2022
·Vol. 12
·期 15
·2700
·
IF 5.719
Lijun Hu,Zhichao Ding,Fei Yan,Kuan Li,Li Feng,Hongqing Wang
Oxygen vacancy manipulation and hierarchical morphology construction in oxygen-containing semiconductors have been demonstrated to be effective strategies for developing high efficiency photocatalysts. In most studies of bismuth-based photocatalysts, hierarchical morphology and crystal defects are achieved separately, so the catalysts are not able to benefit from both features. Herein, using boiling ethylene glycol as the treatment solution, we developed an etching-recrystallization method for the fabrication of 3D hierarchical defective BiOCl at ambient pressure. The target hierarchical 3D-BiOCl is composed of self-assembled BiOCl nanosheets, which exhibit a hexagonal prism-like morphology on a micron scale, while simultaneously containing numerous oxygen vacancies within the crystal structure. Consequently, the target catalyst was endowed with a higher specific surface area, greater light harvesting capability, as well as more efficient separation and transfer of photo-excited charges than pristine BiOCl. As a result, 3D-BiOCl presented an impressive photocatalytic activity for the degradation of tetracycline hydrochloride in both visible light and natural white light emitting diode (LED) irradiation. Moreover, an extraordinary recycling property was demonstrated for the target photocatalyst thanks to its hierarchical structure. This study outlines a simple and energy-efficient approach for producing high-performance hierarchically defective BiOCl, which may also open up new possibilities for the morphological and crystal structural defect regulation of other Bi-based photocatalysts.Keywords:BiOCl;photocatalytic;lattice defects;hierarchical structure;degradation;ambient pressure
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Jingjing He,Hao Chen,Yisong Chen,Xin Su,Peng Zhang,Hongming Xu,Chenglong Zhou
Among the biofuels produced from lignocelluloses, cyclopentanol is a promising candidate. In this study, a constant volume chamber (CVC) is employed to investigate the effects of adding cyclopentanol in diesel with different proportions (0%, 10%, and 20% in volume) on the spray and combustion characteristics. Tests are performed under three injection pressures (100, 120 and 140 MPa). The experimental results in the CVC show that the atomization characteristics of cyclopentanol-diesel blends are better in the early stage of spray and slightly worse in the later stage than those of diesel. As the injection pressure increases, the diesel cyclopentanol blend fuels improve the air fuel mixing. The addition of cyclopentanol has risen the temperature of the flames and cut the soot formation of diesel by 12.7–89.2% under all injection pressure conditions. The addition of cyclopentanol is found to reduce the natural flame luminosity and combustion duration significantly due to the effective combustion process acceleration and is helpful for improving the combustion, especially for CP10. Overall, blending cyclopentanol into diesel has a great soot reduction potential with a low cetane number and improved mixing, and CP10 can be seen as a future alternative fuel, especially under an injection pressure of 140 MPa.
研究领域:
能源科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Xuelin Dong,Yuxiang Xiong,Nan Wang,Zhou Song,Jie Yang,Xiumei Qiu,Lihua Zhu
The analysis of siliceous matrix samples may adopt a two-step pretreatment , which includes melting with ammonium hydrogen fluoride and redissolving with nitric acid . However, the residual of substrate silicon unfavorable to the determination of trace elements in the samples due to serious matrix effects. Here, a new digestion method using simultaneously both ammonium bifluoride and nitric acid under normal pressure was developed for high-purity quartz sand sample. The digestion pretreatment is a two step process: melting/dissolving with both ammonium bifluoride and nitric acid at 200 °C for 2 h, and evaporating the solution at 250 °C to dryness. As confirmed by XRD analysis, silicates in the sample were converted to (NH 4 ) 3 SiF 6 NO 3 in the melting/dissolving step. TGA analysis shows that the generated (NH 4 ) 3 SiF 6 NO 3 could be decomposed and evaporated completely at 250 °C, which ensured a complete removal of silicon by the followed evaporation of the solution at 250 °C. As a result, the followed ICP-OES and ICP-MS analysis needed a solution dilution of only 100 times for the determination of Ca, Mg, Al, Rb, Ba, REE and other trace elements. The new method was applied to the analysis of three certified reference materials, and the results were well consistent with the standard value with RSD% values between 0.62% and 9.73%. Therefore, this method can be applied to the analysis of trace elements in high purity silica-based samples, with the advantages of time-saving, small dilution factor (only 100 times) and low detection limit.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2020
·Vol. 27
·期 4
·1241-1251
·
IF 2.183
Huang Siqi,Wu Xiaoxu,Li Zhi,Shi Long,Zhang Yan,Liu Qiong
In this work, monolithic silica aerogels were prepared in pure water within 4 h by using MTMS as the precursor under ambient pressure drying (APD). The effects of the volume ratio of H 2 O/MTMS, CTAB content and NH 3 ·H 2 O concentration on the properties of MTMS-based aerogels (MSA) were investigated experimentally. The realization of the rapid synthesis of MSA under APD is attributed to getting rid of the aging process, solvent exchange and surface modification. It demonstrates that the microstructure of MSA is comprised of coralloid branches. Furthermore, the greater volume ratio of H 2 O /MTMS, larger CTAB content and smaller NH 3 ·H 2 O concentration cause relatively slimmer coralloid branches, smaller pores and weakened connectivity of skeletons. It also finds that the MSA with a greater volume ratio of H 2 O/MTMS presents larger Young’s modulus and smaller compressive stress, which is because of the correspondingly different microstructures. The as-prepared MSA shows a low density of 0.064 g/cm 3 and a contact angle as high as 143.4°, which provides their potentials for some engineering applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 11
·2641
·
IF 3.1
Jinjing Guo,Kaiqiang Luo,Wenqi Zou,Jun Xu,Baohua Guo
Ambient pressure drying (APD) of silica aerogels has emerged as an attractive method adapting to large-scale production. Spring-back is a unique phenomenon during APD of silica aerogels with volume expansion after its shrinkage under capillary force. We attribute the intense spring-back at elevated drying temperatures to a dense structure formed on the surface and the formation of positive internal pressure. Furthermore, an APD-assisted foaming method with an in situ introduction of NH4HCO3was proposed. NH4HCO3decomposing at drying temperatures hastened the emergence of positive pressure, thereby increasing the expansion volume. Compared to the previous method, the porosity of silica aerogel increased from 82.2% to 92.6%, and mesopore volume from 1.79 cm3g−1to 4.54 cm3g−1. By adjusting the amount of the silicon source, silica aerogels prepared by the APD-assisted foaming method generated higher volume expansion and lower thermal conductivity. After calcination to remove undecomposed ammonium salts, the hydrophobic silica aerogel with a density of 0.112 g cm−3reached a mesopore volume of 5.07 cm3g−1and a thermal conductivity of 18.9 mW m−1·K−1. This strategy not only improves the thermal insulation properties, but also offers a significant advancement in tailoring silica aerogels with specific porosity and mesopore volume for various applications.
研究领域:
材料科学
·
隔热材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Jiayuan Wang,Mingquan Li,Yajie Fu,Cederick Cyril Amoo,Yujia Jiang,Ruiqin Yang,Xu Sun,Chuang Xing,Elton Maturura
Zeolites are vital industrial materials applied widely in the field of heterogeneous catalysis . Porous zeolites are essentially synthesized in the presence of soft or hard templates in processes such as hydrothermal, solvothermal, and ionothermal synthesis. Herein, we demonstrated a facile ambient pressure technique to synthesize NaY zeolite using a glass tube as a reactor and a fluid sealant to create a physical barrier between the reactor contents and the atmosphere. The synthesized zeolite Y was characterized by XRD , SEM, TEM , UV-Raman, N 2 sorption , MAS NMR, and XRF spectroscopy . In comparison to the traditional hydrothermal synthesis routes, the avoidance of high-pressure synthesis apparatus not only reduces safety risks but also significantly improves the yield of zeolite products with a crystallinity of 52% and Si/Al = 3.51. Furthermore, the process is leaner, efficient, and reduces costs. Optimum conditions realized for the synthesis of highly crystalline zeolite Y were 90 °C and 18 h crystallization temperature and period respectively, using 1-dodecanol as a sealant. Subsequently, PEG6000 emerged the best among organic templates investigated to improve porosity while maintaining high crystallinity of the zeolite.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yujia Jiang,Haochen Qi,Jiayuan Wang,Xu Sun,Changjiang Lyu,Peng Lu,Ruiqin Yang,Aqsa Noreen,Chuang Xing,Noritatsu Tsubaki
Zeolites’ great momentum in industrial applications will require an efficient route for their synthesis. The conventional methods for zeolite synthesis normally involve expensive reactor setups, where the crystallization occurs at high-pressure conditions. Herein, we proposed an ambient-pressure synthesis (APS) of the NaA zeolite at 120 °C. The reaction setup simply used a glass tube as a reactor and a low-density liquid as a sealant. The optimum synthesis conditions were obtained by using a methylcellulose template and the polyethylene glycol-400 sealant. Compared with that of the conventional hydrothermal process, the barrier of the sealant over the zeolite gel in the glass tube can significantly reduce the synthesis cost, and it also makes the process much safer than the conventional methods.
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
COMPOSITES COMMUNICATIONS
·
2022
·
IF 7.685
Xin Li,Hao He,Qiang Liu,Chunxia Zhao,Hongbing Chen
Preparation of inexpensive aerogel via ambient-drying is an important goal in aerogel field. In this study, the sol-gel transformation of polyvinyl alcohol (PVOH)/clay was achieved by γ-ray irradiation, followed by solvent exchanging, 1H, 1H, 2H, 2H-Perfluorodecyltrimethoxysilane (FAS) grafting and ambient-drying to obtain a hydrophobic aerogel. Compared with the freeze-drying method, the specific surface area and pore size distribution of the aerogels prepared by ambient-drying obviously increased, which is more favorable for the grafting of FAS. The water contact angle of the resulting aerogel increased to 139.5° after grafting, while the flammability slightly decreased. The compressive modulus, density and specific modulus of aerogels also increased gradually with the increase of irradiation. When the absorbed dose arrived 100 kGy, the compressive modulus, density and specific modulus reached 25.8 MPa, 0.213 g/cm 3 and 118 MPa·cm 3 /g, respectively. This novel method offers an easy and inexpensive way for fabricating hydrophobic aerogel using water soluble raw materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yuanfang Shen,Liangchen Chen,Luping Zhang,Weihang Han,Yurong Chang,Hui Zheng
Photocatalytic conversion of nitrogen to ammonium is a carbon neutralization reaction. Synthesizing suitably modified semiconductor substrate photocatalysts for nitrogen fixation is a challenge and hot topics in recent decades. This research aims to synthesize a photocatalyst with abundant oxygen vacancies and explore its nitrogen fixation performance. Herein, Cobalt oxide@Schiff was synthesized through organic synthesis and hydrothermal method. Its structure and nitrogen fixation properties were explored. It was found that Cobalt oxide@Schiff has an all-day nitrogen fixation performance from air directly, and the rate could reach 2880 μg/(L•h) under sunlight or day and night at normal temperature and pressure. The advantage of this photocatalyst is that the large π bond of the Schiff base ligand could significantly improve the light-trapping ability and the synergistic effect of nitrogen fixation, which provides a new pathway for nitrogen fixation day and night under room temperature and atmosphere pressure.
研究领域:
材料科学
·
环境科学
·
化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Yu-Chuan Zhang,Rong Ding,Peng-Gang Su,Fu-Rong Zeng,Xu-Xu Jia,Zai-Yin Hu,Yu-Zhong Wang,Hai-Bo Zhao
Oriented aerogels, emerging as a new generation of lightweight electromagnetic interference (EMI) materials, often face complex synthesis processes. While creating an orderly oriented microstructure for EMI aerogels through ambient pressure drying (APD) shows promise, it remains a significant challenge. Here, inspired by the directional grown structure of the plant, a new strategy that employs rapid precursor orientation followed by slow cross-linking to achieve the APD of directional EMI aerogels is proposed. This approach demonstrates that low-temperature oriented polymerization of polyaniline enables strong cross-linking with poly(3,4-ethylenedioxythiophene) and alginate, forming a robust conductive directional skeleton and mitigating surface tension issues during mild drying. The resulting aerogel features high conductivity (48.84 S m −1 ), excellent flame retardancy, and impressive compressive strength. Notably, its sturdy frame allows for further enhancement with other functional materials, such as Mxene, through re-processing and re-drying. The tree-branch-like aerogel achieves a significantly improved EMI shielding effectiveness of 50.3 dB across an ultrawideband range of 8.2–40 GHz. This strategy offers a new idea for the straightforward preparation of functional aerogels with programmability and oriented microstructures using ambient drying.
研究领域:
材料科学
·
仿生学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2018
·
IF 2.488
Ting Zhou,Lunlun Gong,Xudong Cheng,Yuelei Pan,Congcong Li,Heping Zhang
The by-product silicon tetrachloride (SiCl 4 ) was usually obtained from polysilicon industry and was a cheaper alternative precursor. An economic method to produce silica aerogel using silicon tetrachloride under ambient pressure drying was presented in this work, which can also solve the pollution problem during the by-product silicon tetrachloride treatment process. The prepared aerogel samples were characterized by scanning electron microscopy, Brunauer-Emmett-Teller analysis, thermal conductivity analysis, contact angle test, Fourier transform infrared spectroscopy and thermogravimetric analysis . It was found that the molar ratio of H 2 O/SiCl 4 could affect the properties of aerogels seriously. The density and thermal conductivity first decreased and then increased as the molar ratio increased from 13 to 32. The porosity showed an opposite trend with the density. Silica aerogel with high specific surface area (856.7 m 2 /g), low density (0.077 m 3 /g) and low thermal conductivity (0.0213 W/m·k) were obtained at the optimal conditions when the molar ratio was 25. The resulting aerogel is also mesoporous material with super hydrophobicity and have a huge application in thermal insulation field.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）