scholarly journals Comparative study of layered tetravalent metal phosphates containing various first-row divalent metals. Synthesis, crystalline structure

2007 ◽  
Vol 5 (2) ◽  
pp. 516-535 ◽  
Author(s):  
László Szirtes ◽  
László Riess ◽  
János Megyeri ◽  
Ernõ Kuzmann
Keyword(s):  
Ion Exchange ◽  
Transition Metal ◽  
Transition Metals ◽  
Comparative Study ◽  
Powder Diffraction ◽  
Layered Structure ◽  
Exchange Method ◽  
X Ray ◽  
Metal Phosphates ◽  
Ion Exchange Method

AbstractThe transition metal forms of α-zirconium-. titanium-, and hafnium phosphates were prepared by ion exchange method. Their structure was investigated by X-ray powder diffraction (XRPD) method. It was found that the transition metal containing phosphates have the same layered structure as the pristine tetravalent metal phosphates, except for the increase of interlayer distance from 7.6 Å to ∼9.5 Å. As a result of the incorporation of transition metals in the layers, the c-axis is increased from ∼15 Å to ∼20 Å (in the case of titanium phosphate to ∼25 Å). All other parameters (a, b and β °) are practically unchanged.

The Syntheses and Characterization of Layered LiNi1-y-zMnyCozO2 Compounds

2002 ◽  
Vol 756 ◽  
Author(s):  
J. Katana Ngala ◽  
Natasha A. Chernova ◽  
Luis Matienzo ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Powder Diffraction ◽  
Layered Structure ◽  
Transition Metal Ions ◽  
Layered Compounds ◽  
Layered Compound ◽  
X Ray ◽  
Initial Capacity

ABSTRACTThe layered compounds of formula LiNi0.4Mn0.6-yCoyO2, for y=0.2, 0.3, and 0.4 and LiNi0.7-yMn0.3CoyO2 for y=0.3, and 0.1 were synthesized at 800°C. X-ray powder diffraction indicates layered structure of R 3m symmetry similar to a-NaFeO2. Rietveld refinement data shows that Mn and Ni increase the tendency of transition metal ions to migrate into the interlayer sites relative to LiCoO2. Both magnetic susceptibility and XPS data support a 2+ oxidation state for Ni and 4+ and 3+ for Mn and Co, respectively. The layered compound LiNi0.4Mn0.4Co0.2O2 shows a high initial capacity of about 200mAh/g when cycled between 2.5V and 4.3 V at 20°C.

Baeyer-Villiger Reaction of Adamantanone over Sn-Containing Hydrotalcite-Like Catalysts

2007 ◽  
Vol 119 ◽  
pp. 163-166 ◽  
Author(s):  
Zhi Qiang Yang ◽  
Sang Eon Park
Keyword(s):  
Hydrogen Peroxide ◽  
Ion Exchange ◽  
Direct Synthesis ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Exchange Method ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ion Exchange Method

Sn-containing hydrotalcite-like compounds were prepared by three different methods such as (i) direct synthesis, (ii) ion-exchange and (iii) grafting. These catalysts were proved to have framework Sn species by powder X-ray diffraction (XRD) analysis and UV-vis spectroscopy. The catalysts prepared by three methods were found to be active and selective for the liquid phase Baeyer–Villiger (BV) oxidation of admantonone using hydrogen peroxide (H2O2) as an oxidant and acetonitrile as a solvent. The Sn-hydrotalcite-like catalysts prepared by ion-exchange method exhibited better catalytic performance than the catalysts prepared by other two methods. Among the ion-exchanged hydrotalacite-like catalysts, 3% Sn ion-exchanged hydrotalcite exhibited superior activity at 30% conversion and 100% selectivity.

Study on Organic Modified of Montmorillonite by Corrosion Inhibitor of Quaternary Ammonium Salts

2013 ◽  
Vol 669 ◽  
pp. 103-107 ◽  
Author(s):  
Jian Guo Sheng ◽  
Ping Zeng
Keyword(s):  
Ion Exchange ◽  
Quaternary Ammonium ◽  
Interlayer Space ◽  
Quaternary Ammonium Salts ◽  
Raw Material ◽  
Ammonium Salts ◽  
X Ray Diffraction ◽  
Exchange Method ◽  
X Ray ◽  
Ion Exchange Method

A series of organic montomorilonite were prepared by using Sodium monanorilonite(Na-MMT) as raw material and quaternary ammonium salts with different chain long as intercalation agents by the way of ion exchange method. Weightlessness experiment showed that intercalated agents could alleviate the corrosion of metal. The MMT and organic MMT (OMMT) were identified by infrared spectra (FTIR) and X-ray diffraction (XRD). The results showed that intercalation agents had intercalated into the interlayer space of MMT, and the spacing of MMT layers had increased from 1.51 nm to 2.94 nm.

Structural Reinvestigation of Alkali Hexatitanate

2011 ◽  
Vol 170 ◽  
pp. 208-212
Author(s):  
Kunimitsu Kataoka ◽  
Norihito Kijima ◽  
Hiroshi Hayakawa ◽  
Junji Akimoto
Keyword(s):  
Ion Exchange ◽  
Single Crystal ◽  
Molten Salt ◽  
Type Structure ◽  
Exchange Method ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Li Ion ◽  
Ion Exchange Method

Na1.614Li0.386Ti6O13 Single crystal was synthesized by a Li+ ion-exchange method from Na2Ti6O13 single crystal in a molten salt of LiNO3. The obtained Na1.614Li0.386Ti6O13 single-crystal is colorless and has the shape of a rod. Na1.614Li0.386Ti6O13 crystallizes in the monoclinic tunnel type structure, space group C2/m, and lattice parameters a = 15.144(2) Å, b = 3.7492(5) Å, c = 9.162(2) Å and β = 99.0131(9)º. The structure was determined by a single-crystal X-ray study and refined to the conventional values of R = 0.0247 and wR = 0.0451 for 969 independent observed reflections.

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