Physicochemical Properties and Catalytic Behavior of the Molecular Sieve SSZ-70

2010 ◽  
Vol 22 (8) ◽  
pp. 2563-2572 ◽  
Author(s):  
Raymond H. Archer ◽  
John R. Carpenter ◽  
Son-Jong Hwang ◽  
Allen W. Burton ◽  
Cong-Yan Chen ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Molecular Sieve ◽  
Catalytic Behavior

Effect of Synthesis Duration on the Physicochemical Properties of Siliceous Mesoporous Molecular Sieve (Si-MMS)

2012 ◽  
Vol 326-328 ◽  
pp. 647-653 ◽  
Author(s):  
Anita Ramli ◽  
Sohail Ahmed ◽  
Suzana Yusup
Keyword(s):  
Physicochemical Properties ◽  
Pore Structure ◽  
Molecular Sieve ◽  
Mesoporous Material ◽  
Mesoporous Molecular Sieve ◽  
Diffraction Peaks ◽  
Adsorption Desorption ◽  
Synthesized Materials ◽  
Synthesis Duration ◽  
Mcm 41

Pure silica mesoporous molecular sieve (MMS) solid has been synthesized at 100°C by hydrothermal process. The effect of synthesis duration from 2 to 10 days has been investigated on the physicochemical properties of mesoporous molecular sieve. Samples were characterized by low angle XRD, N2adsorption-desorption and HRTEM analysis. XRD patterns of the as-synthesized samples showed four well-defined diffraction peaks corresponding to 100, 110, 200 and 210 planes. These peaks are the fingerprint characteristics of MCM-41 mesoporous material. The high intensity diffraction peaks were observed in 8-days sample that define the high ordering of the pores and long range order. N2adsorption-desorption results showed that all samples possessed a type IV isotherm having hysteresis loop of typeH1which is an identification of mesoporous material. Calcined samples exhibited high surface area i.e., 984-1036 m2g-1, pore volume i.e., 1.00-1.13 cm3g-1and average pore diameter i.e., 3.04-3.30 nm. A hexagonal pore structure was found in the synthesized materials by HRTEM analysis, which confirms that the synthesized materials are MCM-41. HRTEM analysis showed the effect of synthesis duration on the materials and found that 8-days sample exhibited highly ordered hexagonal pore structure like honeycomb structure. All the samples were calcined at 550°C to remove the template and to study the changes in the mesoporous framework. The results showed that the mesoporous structure remained intact after calcination at 550°C, indicating that the mesoporous materials exhibit high thermal stability.

Acid Properties of MCM-36 Molecular Sieve and its Catalytic Behavior in Benzene Alkylation with Propylene

2014 ◽  
Vol 1015 ◽  
pp. 434-437 ◽  
Author(s):  
Fei Zhao ◽  
Yu Zhang ◽  
Wen Jing Jiang
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieve ◽  
Acid Sites ◽  
Velocity Space ◽  
Acidic Properties ◽  
Catalytic Behavior ◽  
Benzene Alkylation ◽  
Acid Properties ◽  
Ft Ir ◽  
Excellent Selectivity

Pillared layered MCM-36 zeolite was synthesized from pure MCM-22 precursor with polymeric silica as pillaring agent. Characterization results of acidic properties from FT-IR indicate a decrease in the amounts of Lewis acidic and Brønsted acidic. The catalytic behavior of pillared layered MCM-36 zeolite in benzene alkylation with propylene was studied. It was found that pillared MCM-36 zeolite shows stable catalytic activity in a 200h time-on-stream measurement under a relatively high propylene velocity space. The excellent selectivity to cumene over MCM-36 should be mainly due to the decrease in the amount of Brønsted acidity, while the improvement of the catalytic activity of MCM-36 can be mainly assigned to the presence of a larger amount of structurally accessible acid sites caused by the increment of mesoporous volume in this material.

Effect of lanthanum species on the physicochemical properties of La/SAPO-11 molecular sieve

2017 ◽  
Vol 347 ◽  
pp. 170-184 ◽  
Author(s):  
Yuxiang Liu ◽  
Xinmei Liu ◽  
Lianming Zhao ◽  
Yuchao Lyu ◽  
Lu Xu ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Molecular Sieve

The Physicochemical Properties Of Vpi-7: A Microporous Zincosilicate With Three-Membered Rings

1991 ◽  
Vol 233 ◽  
Author(s):  
Michael J. Annen ◽  
Mark E. Davis ◽  
John B. Higgins ◽  
John L. Schlenker
Keyword(s):  
Physicochemical Properties ◽  
Molecular Sieve ◽  
Natural Zeolite ◽  
Toxic Compounds ◽  
Void Volumes ◽  
Framework Density ◽  
Synthesis Of Materials

ABSTRACTThe synthesis of materials with void volumes in excess of 50% is an ongoing challenge in molecular sieve science. It has been shown that a correlation exists between the minimum framework density (FD) and the smallest ring in which all tetrahedral atoms reside (MINR). Based on this evidence it appears that materials containing 3-membered rings (3MR) will be necessary in order to obtain FDs lower than those currently attainable. Several framework beryllosilicate minerals including the natural zeolite, lovdarite, contain 3MRs. Unfortunately, beryllium can form highly toxic compounds that limit its suitability for many applications. Thus, in this study we have searched for a replacement for Be and have found that zinc is a suitable substitute with respect to the formation of three-membered rings.We report here VPI-7, a novel zincosilicate molecular sieve which contains three-membered rings. The VPI-7 framework contains rings composed of 3–, 4– and 5 T-atoms which form unidimensional 8– and intersecting 9MR channels.

Studies on γA-globulins and α2-macroglobulins. Characterization of γA- and α2-macroglobulins

1968 ◽  
Vol 46 (3) ◽  
pp. 211-216 ◽  
Author(s):  
Benjamin E. Sanders ◽  
Yang H. Oh
Keyword(s):  
Ion Exchange ◽  
Physicochemical Properties ◽  
Human Plasma ◽  
Molecular Sieve ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Normal Human Plasma ◽  
Γ Globulins ◽  
Normal Human

Fractionation into several individual components was achieved from Cohn's Fraction III of human plasma by the successive application of separation principles that depend on solubility, charge, and size (precipitation, ion-exchange chromatography, and molecular-sieve chromatography methods). Characterization was made by various electrophoretic procedures such as microzone on cellulose acetate, disc on acrylamide gel, and immunoelectrophoresis, and includes some physicochemical properties of the purified proteins. There are found to be various components of γ-globulins, α2-macroglobulins, β-glycoproteins, β-lipoproteins, and other minor proteins in Cohn's Fraction III of normal human plasma. The physicochemical properties of two γA-globulins and two α2-macroglobulins were investigated.

Sign in / Sign up

Export Citation Format

Share Document