FUEL
·
2020
·
IF 5.578
Ze Zhang,Jun Cheng,Yanxia Zhu,Hao Guo,Weijuan Yang
To promote hydrocracking and isomerization activities of bifunctional catalyst for the conversion of methyl palmitate into jet biofuel, phosphotungstic acid (HPW) loaded on Ni/MCM-41 catalyst enhanced strong acidity to strengthen conversion pathways of hydrocracking and isomerization. In the bifunctional catalytic system, Ni catalyzed hydrodeoxygenation and dehydrogenation of methyl palmitate to produce 1-pentadecene, while acid sites catalyzed further conversion of 1-pentadecene to produce jet fuel range hydrocarbons. Quantum chemistry calculation showed that activation energy in chemisorption process of 1-pentadecene onto acid sites significantly reduced from 203.9 kJ/mol with MCM-41 to 81.6 kJ/mol with HPW. Since bond order of β-scission site in 1-pentadecene over HPW was 0.93% lower than that over MCM-41, and Hirshfeld atomic charge of carbenium ion in 1-pentadecene over HPW (0.0722) was much higher than that over MCM-41 (0.0473), HPW showed better catalytic activities than MCM-41 in both hydrocracking and isomerization processes. The overall selectivity of jet biofuel increased to 86.1% with 47.1% n-alkane selectivity and 8.3% iso-alkane selectivity, due to improved strong acid density from 0.563 to 0.730 mmol/g over 20% HPW-Ni/MCM-41 catalyst.
研究领域:
催化化学
·
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2017
·Vol. 130
·期 2
·935-941
·
IF 1.953
Han Lipeng,Ma Guixiang,Xie Shaolei,Sun Jinhe,Jia Yongzhong,Jing Yan
Shape-stabilized composite phase change materials composed of sebacic acid (SA) and MCM-41 were prepared by a facile blending and impregnating method. Various characterization techniques were carried out to characterize their structural and thermal properties, including thermogravimetry (TG) analyses and differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy. The XRD and FT-IR results indicated the interactions between SA and MCM-41, such as the capillary force and the hydrogen bonding, resulting in the confined crystallization process. As a result, the SA that was confined was amorphous. The TG analysis results showed that the presence of MCM-41 practically resulted in an overlapping of the two decomposition stages. The DSC analysis demonstrated that a decrease in the SA content was accompanied by a continuous decrease in the melting point and phase change enthalpy of the composites.
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
POWDER TECHNOLOGY
·
2012
·
IF 2.08
Chongwen Jiang,Aixian Su,Xuemei Li,Tao Zhou,Dewen He
A series of MCM-41 mesoporous molecular sieves with different Si/Al molar ratio has been synthesized by hydrothermal crystalline method using cetyltrimethylammonium bromide as structural template, sodium silicate as silica source and sodium aluminate as aluminum source in alkaline solution. The results show that all the samples have hexagonal mesoporous structure. The secondary restructured materials exhibit well defined structure and the long distance order of the mesopores . The mesoporous structure for Si/Al = 25 MCM-41 with high specific area can be maintained after hydrothermal stability test in boiling water more than 12 h, showing that the secondary restructure can enhance the hydrothermal stability of MCM-41 with the pore diameter size of larger than 3.3 nm and BET surface area of more than 800 m 2 ·g − 1 . Furthermore, MCM-41 with Si/Al = 25 has the optimal hydrothermal stability due to the introduction of Al atom.
研究领域:
材料科学
·
无机化学
·
纳米材料
·
多孔材料
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Wenhui Zou,Yingcen Liu,Caicheng Song,Hua Lin,He Huang,Wanyue Ye,Rongwen Lu,Shufen Zhang
A series of PdO@MCM-41-x was in situ synthesized by a facile one-pot method, and their catalytic performance for dehydrogenation of formic acid was investigated. The PdO nanoparticles were immobilized in MCM-41 channel with small size of 2.2–2.5 nm due to the confinement of mesoporous silica . The initial turnover frequency (TOF) of as-prepared catalyst can reach 1096 h −1 at 323 K with 100% hydrogen selectivity. The hydrogen production activity was better than that of catalyst priorly reduced by hydrogen because of the gradual reduction of PdO nanoparticles and generation of fresh Pd(0) during the formic acid dehydrogenation process, which was confirmed by XPS characterization and catalytic system monitoring. It provides a new way for the preparation of simple and efficient catalysts for hydrogen production , which has great application potential.
研究领域:
化学
·
催化材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 7
·4927-4938
·
IF 2.599
Liu Ran,Zhang Juan,Xu Zhice,Zhao Dishun,Sun Shuang
Iron phthalocyanine (PcFe) was loaded on Ti-MCM-41 as visible light photocatalyst (R-PcFe/Ti-MCM-41). Dibenzothiophene (DBT) was photooxidized using R-PcFe/Ti-MCM-41 as a photocatalyst, air as an oxidant, and ionic liquid as the extraction agent during visible light irradiation at room temperature and ambient conditions. The results indicated that photocatalytic efficiency of the amino iron phthalocyanine (NH 2 -PcFe)/Ti-MCM-41 was superior to the other substituent groups. The DBT content in the model oil decreased from 1000 to 44 μg/mL with 95.6% removal rate under the optimal reaction conditions (model oil 10 mL, photocatalyst NH 2 -PcFe/Ti-MCM-41 0.02 g, loading amount of NH 2 -PcFe 0.3 g/g, air flow rate 100 mL/min, reaction time 2 h, room temperature). The kinetics of photocatalytic oxidation of DBT follows first-order kinetics with a rate constant of 1.319 h −1 and halftime of 0.525 h. The photocatalyst NH 2 -PcFe/Ti-MCM-41 was reused for five times, and the catalytic activity decreased slightly. The photocatalytic oxidation system demonstrated significant desulfurization effects on different sulfur compounds and real gasoline, and the sulfur content of the actual gasoline could be reduced from 1000 to 78 ppm.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2011
·Vol. 22
·期 12
·1497-1500
·
IF 0.775
Xiao Zheng Lan,Hai Rong Pei,Chuan Xian Cheng
Phase behavior of binary system of bromobenzene–chlorobenzene (C 6 H 5 Br–C 6 H 5 Cl) confined in SBA-15 and MCM-41 (pore diameter 8 nm, 3.8 nm, respectively) has been investigated by means of differential scanning calorimetry (DSC). Phase diagram of C 6 H 5 Br–C 6 H 5 Cl system confined in SBA-15 is a type of the complete miscible both in liquid and solid state, the same phase behavior as the bulk system. However, the phase diagram comprises only one boundary line, which is shifted down 22–36 K with respect to the bulk system. C 6 H 5 Br, C 6 H 5 Cl or the mixture within nanopores of MCM-41 is nonfreezing. The different phase behavior of the system confined in SBA-15 and MCM-41 is thought mainly due to the relative size of pore to molecule.
研究领域:
物理化学
·
材料科学
·
纳米科技
·
热力学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yan Chen,Ying Liu,Junhao Li,Chunli Zhao,Yougui Yang,Ling He,Meng Wu,Qi Wang,Yong Yang,Chunjian Wang,Dacheng Zhou,Jianbei Qiu
Hydrochromic materials have received much attention in anticounterfeiting due to their reversible photoemission properties toward water. However, existing hydrochromic materials usually suffer from slow hydrochromic response and limited stability, repeatability, and color tunability. This paper found for the first time that CsPbBr 3 /Cs 4 PbBr 6 composites with quantum-limited domain effects had reversible hydrochromism. CsPbBr 3 /Cs 4 PbBr 6 composites were successfully synthesized in molecular sieve MCM-41 using an improved mechanochemical method. The composites underwent a reversible phase transition from Cs 4 PbBr 6 /CsPbBr 3 to CsPbBr 3 upon treatment with a trace amount of water, the photoluminescence colors underwent a change from blue to green, and reversion occurred due to heating. Mechanistic investigation revealed that quantum dots underwent soft agglomeration due to van der Waals forces in polar solvent environments, affecting the action of quantum domain-limiting effects. Therefore, organic solvents with different polarities can cause different degrees of reversible discoloration of the material. This study provides new ideas for understanding the phase transition and agglomeration of metal halide perovskite quantum dots in polar solvent environments. Additionally, it offered new options for aqueous color-changing materials and organic solvent polar detection materials.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 22
·3654
·
IF 2.972
Mingxuan Ma,Xiaoyu Ma,Suping Cui,Tingting Liu,Yingliang Tian,Yali Wang
A series of MCM-41 molecular sieves with different molar ratio of template to silicon were synthesized through hydrothermal synthesis method by using cetyltrimethylammonium bromide (CTAB) as the template, diatomite as the silicon source. By using impregnation method, the Mn-Ce/MCM-41 SCR molecular sieve-based catalysts were prepared. The results observed that when the molar ratio of template to silicon was 0.2:1, the MCM-41 as catalyst carrier has the highest surface area and largest pore volume, it also presented typically ordered hexagonal arrays of uniform channels. The denitration catalytic material based on this carrier has a high number of Lewis acidic sites, and the denitration efficiency can reach more than 93%.
研究领域:
环境催化
·
材料科学
·
化学工程
·
大气污染控制
·
无机多孔材料
✓ 已验证
DOI
高影响因子
PROGRESS IN REACTION KINETICS AND MECHANISM
·
2017
·
IF 0.682
Jiao Jing Zhang,Wen Yi Wang,Guo Jian Wang,Cheng Kai,Hua Song,Lu Wang
A model natural gas consisting of hydrogen sulfide, nitrogen and oxygen mixture was used to simulate materials to test the performance of an amine-modified MCM-41 adsorbent prepared by the impregnation method. The adsorbent was characterised by X-ray diffraction analysis, Brunauer–Emmett–Teller analysis, Fourier-transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopy. The results showed that more molecules are able to penetrate the pores following modification, resulting in rapid structural collapse, thus lowering the diffraction intensity. Although the capacity of amine-modified MCM-41 decreased the physical adsorption, chemisorption increased significantly. (3-Aminopropyl)trimethoxysilane/MCM-41 was found to exhibit a good performance for H2S desulfurisation. At 45 °C the breakthrough time was 186 min, the saturated sulfur capacity was 134.38 mg g−1 and the degree of desulfurisation was 54.19%. The adsorption isotherm and kinetics were investigated and the relevant parameters were obtained. The results showed that the adsorption isotherm could be well fitted by the Langmuir model and the maximum adsorption capacities increased with increase of temperature. The adsorption kinetics could be represented by the Bangham model, which suggested that chemical reaction seemed significant in the rate-controlling adsorption step. The adsorption process was spontaneous and exothermic.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 46
·27050-27059
·
IF 3.049
Xia Wang,Wulan Zeng,Hongyan Zhang,Dan Li,Hongjing Tian,Xiude Hu,Qian Wu,Chunling Xin,Xiaoyu Cao,Wenjing Liu
To reduce the cost of CO2 capture, polyethylene polyamine (PEPA), with a high amino density and relatively low price, was loaded into MCM-41 to prepare solid sorbents for CO2 capture from flue gases. In addition, methoxypolyethylene glycol (MPEG) was codispersed and coimpregnated with PEPA to prepare composite sorbents. The pore structures, surface functional groups, adsorption and regeneration properties for the sorbents were measured and characterized. When CO2 concentration is 15%, for 30, 40 and 50 wt% PEPA-loaded MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.15, 1.47 and 1.66 mmol g−1 at 60 °C; for 30 wt% PEPA and 20 wt% MPEG, 40 wt% PEPA and 10 wt% MPEG, and 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.97, 2.22 and 2.25 mmol g−1 at 60 °C; the breakthrough and equilibrium adsorption capacities for 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41 respectively reached 2.01 and 2.39 mmol g−1 at 50 °C, all values showed a significant increase compared to PEPA-modified MCM-41. After 10 regenerations, the equilibrium adsorption capacity for codispersed MCM-41 was reduced by 5.0%, with the regeneration performance being better than that of PEPA-loaded MCM-41, which was reduced by 7.8%. The CO2-TPD results indicated that the mutual interactions between PEPA and MPEG might change basic sites in MCM-41, thereby facilitating active site exposure and CO2 adsorption.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2022
·Vol. 24
·期 3
·1-12
·
IF 2.533
Cao Xiaoyan,Wang Kaijun,Mao Qifan,Gu Zhenggui,Wang Fang
The fabrication of low-cost, recyclable, reusable, and heterogeneous catalysts is of considerable significance for green chemistry. In this study, a nanocomposite catalyst, MCM-41-supported Zn–Co double metal cyanide (MCM-41@DMC), was prepared using the synchronous dropping method. Thereafter, the composition, crystal structure, complexing state, morphology, and thermal stability of the catalyst were characterised using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis, and thermogravimetry. The effects of different organic ligands on the catalytic activity of samples were evaluated, and the results showed that ethyl acetoacetate exhibited the best catalytic activity owing to its ketone coordination. The use of the MCM-41 support was beneficial for improving the catalytic activity because it reduced the crystallinity and substantially increased the external specific surface area of the catalyst. The experimental results pertaining to the use of the MCM-41@DMC catalyst in the fabrication of polypropylene glycol showed that the conversion of propylene oxide and molecular weight reached 90.6% and 2900, respectively. This study provides a new strategy for the green synthesis of poly(propylene glycol) products.
研究领域:
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Lina Zhao,Zeyu Wu,Zhenhua Wang,Zhe Bai,Wang Sun,Kening Sun
For developing the reversible lithium metal anode, constructing an ideal solid electrolyte interphase (SEI) by regulating the Li+ solvation structure is a powerful way to overcome the major obstacles of lithium dendrite and limited Coulombic efficiency (CE). Herein, spherical mesoporous molecular sieve MCM-41 nanoparticles are coated on a commercial PP separator and used to regulate the Li+ solvation structure for lithium metal batteries (LMBs). The regulated solvation structure exhibits an agminated state with more contact ion pairs (CIPs) and ionic aggregates (AGGs), which successfully construct a homogeneous inorganic-rich SEI in the lithium anode. Meanwhile, the regulated solvation structure weakens the interaction between the solvents and Li+, resulting in low Li+ desolvation energy and uniform Li deposition. Thus, a high CE (∼96.76%), dendrite-free Li anode, and stable Li plating/stripping cycling for approximately 1000 h are achieved in the regulated carbonate-based electrolyte without any additives. Therefore, regulating the Li+ solvation structure in the electrolyte by employing a mesoporous material is a forceful way to construct an ideal SEI and harness lithium metal.
研究领域:
材料科学
·
电化学
✓ 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）