Synthetic and catalytic studies of inorganically pillared and organically pillared layered double hydroxides

Wang, J.Don; Serrette, G.P.D.; Tian, Ying; Clearfield, Abraham

doi:10.1016/0169-1317(95)00018-y

Cited by 39 publications

(19 citation statements)

References 13 publications

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“…Layered double hydroxide phases (LDHs) or hydrotalcite-like solids are of interest to these studies due to their ability to retain very wide range of different cations (like, Li + , Ba 2+ , Mg 2+ , Fe 2+ , Ni 2+ , Al 3+ , Fe 3+ , Cr 3+ , Ga 3+ , Sc 3+ , Zr 4+ , etc.) [1][2][3][4][5][6][7] and especially due to their anion-exchange properties (substitutions of I − , Br − , Cl − , OH − , CO 3 2− , SO 4 2− , Fe(CN) 6 4− , carboxylates, sulfonates or dicarboxylates C n H 2n (CO 2 − ) 2 , etc.) [8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and stability properties of Cl-bearing hydrotalcite-pyroaurite solids

Rozov¹,

Curtius²,

Neumann³

et al. 2012

Radiochimica Acta

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A layered double hydroxides (LDH) hydrotalcite-pyroaurite solid solution series (Mg 1−x Fe(II) x ) 3 Al 1 Cl 1 · nH 2 O with variable xFe solid = Fe 2+ /(Fe 2+ + Mg 2+ ) iron mole fractions were studied in co-precipitation experiments at T = 25, 40, 45, 50, 55 and 60 • C and pH = 10.00 ± 0.05. The compositions of the solids and reaction solutions were determined using ICP-OES, EDX (Mg, Al, Fe) and TGA techniques (Cl − , OH − , H 2 O). Powder X-ray diffraction was applied for phase identification and determination of unit-cell parameters a o = b o and c o from Bragg evaluation. Syntheses products containing xFe solid > 0.13 display additional X-ray patterns attributed to the mixture of iron oxides and hydroxides. On the other side, precipitates with 0 ≤ xFe solid ≤ 0.13 show only X-ray reflexes typical for pure LDH compositions. Moreover, in this case unit-cell parameters a o = b o as a function of xFe solid follow Vegard's law corroborating the existence of a continuous solid solution series. TGA data demonstrated the temperatures at which interlayer H 2 O molecules and Cl − -anions are lost, and at which temperatures dehydroxylation of brucite-like layer occurs. Based on detailed analyses of TGA curves it was established that the increase of xFe solid does not result in a visible change of the thermal stability of hydrotalcite-pyroaurite solids. From the chemical analyses of both the solids and the reaction solutions after syntheses, preliminary Gibbs free energies of formation were estimated by using GEMS-PSI code package. Values of G • f (Hydrotalcite) = −3619.04 ± 15.27 kJ/mol and G • f (Pyroaurite) = −2703.61 ± 191.93 kJ/mol were found at 298.15 K. A comparison of our estimate with G • f value −3746.90 ± 11.00 kJ/mol for CO 3 2− -bearing hydrotalcite presented in our previous studies, denotes the effect of intercalated anion on the aqueous solubilities of LDH when Cl-containing solids have to be more soluble than CO 3 2− -bearing substances. Estimation of the standard molar entropy of the hydrotalcite end-member by applying Helgeson's methods and using results of co-precipitation experiments at variable temperatures let us to conclude that derivation of more precise S • f values would require calorimetric measurements.

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Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and stability properties of Cl-bearing hydrotalcite-pyroaurite solids

Rozov¹,

Curtius²,

Neumann³

et al. 2012

Radiochimica Acta

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“…and organic (aliphatic carboxylates, sulphonates, phosphonates, porphyrins, phthalocyanines, etc.) anions5–17 have been intercalated. Consequently, they can be considered interesting host–guest materials with numerous applications, among them the preparation of new composite materials.…”

Section: Introductionmentioning

confidence: 99%

Mg,Al layered double hydroxides with intercalated indomethacin: Synthesis, characterization, and pharmacological study

Arco

Cebadera

Gutiérrez

et al. 2004

Journal of Pharmaceutical Sciences

179

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“…Layered double hydroxides (LDHs) or hydrotalcite-like solids are of interest of these studies due to their unique properties to immobilize very wide range of cations (like, Li + , Ba 2+ , Mg 2+ , Fe 2+ , Ni 2+ , Co 2+ , Eu 3+ , Fe 3+ , Cr 3+ , Ga 3+ , Sc 3+ , Zr 4+ , etc.) [1][2][3][4][5][6][7][8][9] and especially due to their anion-exchange properties (substitution of I − , Br − , Cl − , OH − , CO 3 2− , SO 4 2− , Fe(CN) 6 4− , carboxylates, sulfonates or dicarboxylates C n H 2n (CO 2 − ) 2 , etc.) [10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Preparation, characterization and thermodynamic properties of Zr-containing Cl-bearing layered double hydroxides (LDHs)

2015

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Synthetic and catalytic studies of inorganically pillared and organically pillared layered double hydroxides

Cited by 39 publications

References 13 publications

Synthesis, characterization and stability properties of Cl-bearing hydrotalcite-pyroaurite solids

Synthesis, characterization and stability properties of Cl-bearing hydrotalcite-pyroaurite solids

Mg,Al layered double hydroxides with intercalated indomethacin: Synthesis, characterization, and pharmacological study

Preparation, characterization and thermodynamic properties of Zr-containing Cl-bearing layered double hydroxides (LDHs)

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