scholarly journals Nanoporosity of MCM-41 Materials and Y-Zeolites Created by Deposition of Tournefortia hirsutissima L. Plant Extract

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Miguel Angel Hernández ◽  
Gabriela Itzel Hernández ◽  
Roberto Portillo ◽  
Martha Alicia Salgado ◽  
Fernando Rojas ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Textural Properties ◽  
Shape Selectivity ◽  
Molar Ratio ◽  
Y Zeolites ◽  
Organic Extract ◽  
Inorganic Substrates ◽  
Inorganic Supports ◽  
Outer Area ◽  
Mcm 41

Hybrid materials based on MCM-41 silica and Y-zeolites with a variable Si/Al ratio and an appropriate countercationic composition were prepared by impregnating inorganic substrates with an organic extract. The organic phase was previously characterized by GC-MS and IRTF, while XRD, SEM, TEM, N2-physisorption, and TPD of NH3 were used to analyze the selected inorganic supports. The effect of size- and shape-selectivity was manifested in MCM-41 and Y-zeolites. Texture results confirm that the extract containing relatively large branched organic molecules is deposited in the internal voids of MCM-41 material and on the outer area of Y-zeolites. In the case of Y-zeolites, the results demonstrate the effect of the SiO2/Al2O3 molar ratio and countercations on the textural properties of the samples.

Synthesis and Catalytic Activity of Ni/Ce-MCM-41 Mesoporous Catalysts for Hydrogen Production

2010 ◽  
Vol 1279 ◽  
Author(s):  
J. A. Wang ◽  
J. C. Guevara ◽  
L.F. Chen ◽  
J. Salmones ◽  
M. A. Valenzuela ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mesoporous Materials ◽  
Textural Properties ◽  
Molar Ratio ◽  
High Catalytic Activity ◽  
Strong Temperature Dependence ◽  
Structural Regularity ◽  
Cerium Ion ◽  
Ion Substitution ◽  
Mcm 41

AbstractCe-containing MCM-41 mesoporous materials with large surface area and ordered pore structure system have been possible to be synthesized through a surfactant-assisted approach. The textural properties and structural regularity of the materials varied with the Si/Ce molar ratio. It is found that the band at 970 cm-1 in the FTIR spectrum of the Ce-MCM-41 mesoporous materials might be used as an indicator of the formation of the Ce-O-Si bond and its intensity as a measure of a degree of cerium ion substitution in the framework of Si-MCM-41. When Ni was loaded on the Ce-MCM-41 support, the Ni/Ce-MCM-41 catalysts show high catalytic activity which has strong temperature dependence. The methane conversion over these catalysts reached 60-75 % with a 100 % selectivity towards hydrogen.

scholarly journals Silica Monolith for the Removal of Pollutants from Gas and Aqueous Phases

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1316
Author(s):  
Vanessa Miglio ◽  
Chiara Zaccone ◽  
Chiara Vittoni ◽  
Ilaria Braschi ◽  
Enrico Buscaroli ◽  
...  
Keyword(s):  
Rhodamine B ◽  
Water Solution ◽  
Synthesis Method ◽  
Textural Properties ◽  
Adsorption Properties ◽  
Water Soluble ◽  
Silica Monoliths ◽  
Physico Chemical ◽  
Gaseous Toluene ◽  
Mcm 41

This study focused on the application of mesoporous silica monoliths for the removal of organic pollutants. The physico-chemical textural and surface properties of the monoliths were investigated. The homogeneity of the textural properties along the entire length of the monoliths was assessed, as well as the reproducibility of the synthesis method. The adsorption properties of the monoliths for gaseous toluene, as a model of Volatile Organic Compounds (VOCs), were evaluated and compared to those of a reference meso-structured silica powder (MCM-41) of commercial origin. Silica monoliths adsorbed comparable amounts of toluene with respect to MCM-41, with better performances at low pressure. Finally, considering their potential application in water phase, the adsorption properties of monoliths toward Rhodamine B, selected as a model molecule of water soluble pollutants, were studied together with their stability in water. After 24 h of contact, the silica monoliths were able to adsorb up to the 70% of 1.5 × 10−2 mM Rhodamine B in water solution.

scholarly journals Structural and Magnetic Properties of Potassium-Doped 2,3-DiMethylnaphthalene

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 608
Author(s):  
Xiao-Lin Wu ◽  
Ren-Shu Wang ◽  
Hui Yang ◽  
Jie Zhang ◽  
Ming-An Fu ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Organic Molecules ◽  
Magnetic Measurements ◽  
Ring Structure ◽  
Molar Ratio ◽  
First Principles Calculations ◽  
Paramagnetic Behavior ◽  
Polycyclic Aromatic ◽  
Metal Doped ◽  
Derivatives Of

The development of potential magnetic materials in metal-doped polycyclic aromatic hydrocarbons has been a research hotspot in recent years. Here we have successfully synthesized stable potassium-doped 2,3-dimethylnaphthalene samples. The combination of first-principles calculations and XRD results identifies that doping of potassium into 2,3-dimethylnaphthalene forms a monoclinic structure with a molar ratio of 1:2 between potassium and molecule. The red shifts in the Raman spectra indicate that potassium 4s electrons are transferred to the organic molecules. The magnetic measurements show that the doped materials exhibit a temperature-independent magnetization in the temperature region of 1.8–300 K, which is consistent with the Pauli paramagnetic behavior. This is distinct from the diamagnetism of pristine material. Compared to the previous focus on benzene ring structure, our study of aromatic hydrocarbon derivatives of benzene ring opens a new route for the development of this field.

Photoinduced charge separation in microporous and mesoporous materials

2011 ◽  
Vol 89 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Ranjit T. Koodali
Keyword(s):  
Mesoporous Materials ◽  
Charge Separation ◽  
Organic Molecules ◽  
Microporous Materials ◽  
Photoinduced Charge Separation ◽  
Photoinduced Charge ◽  
Mcm 41

A review of photoinduced charge separation of organic molecules in microporous and mesoporous materials is presented. In particular, the photoionization of N-alkylphenothiazine (PCn), N,N,N′,N′-tetramethylbenzidine (TMB), and porphyrin in microporous materials, such as zeolites, aluminophosphates (AlPOs), silicoaluminophosphates (SAPOs), and mesoporous materials, such as MCM-41, MCM-48, and SBA-15, is discussed.

Removal of sulfur-containing organic molecules adsorbed on inorganic supports by Rhodococcus Rhodochrous spp.

2016 ◽  
Vol 39 (2) ◽  
pp. 241-245 ◽  
Author(s):  
P. Carvajal ◽  
M. Alejandro Dinamarca ◽  
P. Baeza ◽  
E. Camú ◽  
J. Ojeda
Keyword(s):  
Organic Molecules ◽  
Rhodococcus Rhodochrous ◽  
Inorganic Supports ◽  
Sulfur Containing

Preparation and characterization of poly(styrenemethacrylic acid)/MCM-41 core/shell nanocomposite microspheres

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Yansheng Zhao ◽  
Xingji Ma ◽  
Yongmei Liu ◽  
Guangwei Yuan ◽  
Meijuan Guo ◽  
...  
Keyword(s):  
Self Assembly ◽  
Cetyltrimethylammonium Bromide ◽  
Average Diameter ◽  
Molar Ratio ◽  
Core Shell ◽  
Acidic Media ◽  
Assembly Method ◽  
20 Nm ◽  
Mcm 41

AbstractIn acidic media, poly(styrene-methacrylic acid)/MCM-41 [P(St- MAA)/MCM-41] core/shell microspheres were synthesized using monodisperse P(St-MAA) particles contained in soap-free emulsion and cetyltrimethylammonium bromide as co-templates by adsorption self-assembly method. The effects of P(St- MAA) composition on shell structure of the core/shell microspheres were investigated. The morphology and composition of P(St-MAA)/MCM-41 microspheres were characterized by TEM, XRD and FTIR. The results show that the ordering degree of MCM-41 shells increased as the molar ratio of MAA to St increased. When n(MAA)/n(St) is 0.2, the average diameter and the shell thickness of nanocomposite microspheres are about 170 nm and 20 nm, respectively.

scholarly journals Low Temperature NH3-SCR over Mn-Ce Oxides Supported on MCM-41 from Diatomite

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3654 ◽  
Author(s):  
Mingxuan Ma ◽  
Xiaoyu Ma ◽  
Suping Cui ◽  
Tingting Liu ◽  
Yingliang Tian ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Synthesis Method ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Catalyst Carrier ◽  
Nh3 Scr ◽  
Catalytic Material ◽  
Lewis Acidic Sites ◽  
Acidic Sites ◽  
Mcm 41

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%.

Synthesis and Characterization of Super-Molecular Ionic Liquids

2011 ◽  
Vol 197-198 ◽  
pp. 906-910
Author(s):  
Hui Ru Liu ◽  
Li Qiang Lv ◽  
Xing Chen Zhang
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Melting Point ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Raw Materials ◽  
Ammonium Thiocyanate ◽  
Molar Ratio ◽  
Molecular Ion

This study concerned a novel super-molecular ionic liquid synthesized by ammonium thiocyanate and caprolactam. The physical characters such as melting point and electric conductivity were investigated. Results showed that the melting point is -12.2°C at the molar ratio of 3:1 (caprolactam/ammonium thiocyanate), which is much lower than raw materials. The electric conductivities of synthesized ionic liquids were close to that of imidazole ILs. The structure of ionic liquid was characterized by IR,1HNMR and quantum chemical calculations. It was shown that the NH4+cation connected with caprolactam organic molecules by hydrogen bonds, leading to the forming of a super-molecular ion. The electrostatic attraction of super-molecular ion with anion was decreased because of the larger volume of super-molecular ion than original cation, thus the melting point decreased. The key properties that distinguish super-molecular ionic liquid from other ILs were the presence of supermolecular ion, which can be used to build up a hydrogen-bonded network. This type ion liquid was named as super-molecular ion liquid.

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