scholarly journals Synthesis of Mg-Fe layered double hydroxides and its application as catalyst for Friedel-Crafts benzoylation

2016 ◽  
Vol 19 (4) ◽  
pp. 185-193
Author(s):  
Phuong Thi Minh Nguyen ◽  
Phuong Hoang Tran ◽  
Chinh Quoc Nguyen
Keyword(s):  
Metal Oxides ◽  
Layered Double Hydroxides ◽  
Coprecipitation Method ◽  
Mixed Metal Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Metal ◽  
Before And After ◽  
Double Hydroxides

Mg-Fe layered double hydroxides were synthesized by the coprecipitation method with different of Mg/Fe ratio (2/1, 3/1 and 4/1) and then were thermally transformed into mixed metal oxides. The obtained materials before and after the calcination at 450 oC were characterized by X-ray diffraction (XRD), SEM, BET, TGA, ICP. The samples were used as a catalyst for Friedel-Crafts benzoylation reactions. The catalyst can be easily separated and recycled compared to the traditional one.

scholarly journals Synthesis and characterization of layered double hydroxides with different cations (Mg, Co, Ni, Al), decomposition and reformation of mixed metal oxides to layered structures

2011 ◽  
Vol 9 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Kristina Klemkaite ◽  
Igoris Prosycevas ◽  
Ricardas Taraskevicius ◽  
Alexander Khinsky ◽  
Aivaras Kareiva
Keyword(s):  
Metal Oxides ◽  
Layered Double Hydroxides ◽  
Xrd Analysis ◽  
Layered Structures ◽  
Magnesium Nitrate ◽  
Mixed Metal Oxides ◽  
X Ray ◽  
Mixed Metal ◽  
Different Temperatures ◽  
Double Hydroxides

AbstractThree layered double hydroxides (LDH) [Mg1−xAlx(OH)2]x+(Am−)x/m]·nH2O and [MII 1−xMIII x (OH)2]x+(Am−)x/m]·nH2O (MII — Mg, Co, Ni; MIII — Al; A — CO3 2−) were successfully synthesized by the low supersaturation method. The as-synthesized LDH samples were thermally decomposed and the derived mixed metal oxides reformed back to layered structures in water and magnesium nitrate media at different temperatures. All synthesized samples were characterized by X-ray diffraction (XRD) analysis, thermogravimetric (TG) analysis, X-ray fluorescence (XRF) analysis and scanning electron microscopy (SEM). The results of XRD and XRF analyses showed that single-phase layered double hydroxides were formed during synthesis and reformation. It was demonstrated, that a partially substituted by cobalt and nickel LDH samples also show memory effect. The crystallite size of regenerated LDH depends on the regeneration media, temperature and chemical composition. The LDH samples after regeneration consist of large particles with sharp edges along with a large amount of smaller particles

scholarly journals Recent advance on VOCs oxidation over layered double hydroxides derived mixed metal oxides

2020 ◽  
Vol 41 (4) ◽  
pp. 550-560 ◽  
Author(s):  
Shuangde Li ◽  
Dongdong Wang ◽  
Xiaofeng Wu ◽  
Yunfa Chen
Keyword(s):  
Metal Oxides ◽  
Layered Double Hydroxides ◽  
Mixed Metal Oxides ◽  
Mixed Metal ◽  
Double Hydroxides

Selective hydrogenation of 2-pentenal using highly dispersed Pt catalysts supported on ZnSnAl mixed metal oxides derived from layered double hydroxides

2020 ◽  
Vol 10 (4) ◽  
pp. 1106-1116
Author(s):  
Huanjun Wang ◽  
Xiaocheng Lan ◽  
Shiqing Wang ◽  
Babar Ali ◽  
Tiefeng Wang
Keyword(s):  
Metal Oxides ◽  
Layered Double Hydroxides ◽  
Selective Hydrogenation ◽  
High Selectivity ◽  
Mixed Metal Oxides ◽  
Pt Catalysts ◽  
Mixed Metal ◽  
Highly Dispersed ◽  
Double Hydroxides

Highly dispersed Pt catalysts supported on ZnSnAl mixed metal oxides showed high selectivity for 2-pentenol in selective hydrogenation of 2-pentenal.

scholarly journals Characterization of Mixed-Metal Oxides Using Synchrotron-Based Time-Resolved x-ray Diffraction and x-ray Absorption Spectroscopy

1999 ◽  
Vol 590 ◽  
Author(s):  
José A. Rodriguez ◽  
Jonathan C. Hanson ◽  
Joaquín L. Brito ◽  
Amitesh Maiti
Keyword(s):  
Metal Oxides ◽  
Density Functional ◽  
Chemical Properties ◽  
Local Symmetry ◽  
Mixed Metal Oxides ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Mixed Metal ◽  
X Ray Absorption

ABSTRACTExperiments are described showing the utility of synchrotron-based time-resolved x-ray diffraction (TR-XRD) and x-ray absorption near-edge spectroscopy (XANES) for characterizing the physical and chemical properties of mixed-metal oxides that contain Mo and a second transition metal (Fe, Co or Ni). TR-XRD was used to study the transformations that occur during the heating of a FeMoO4/Fe2(MoO4)3 mixture and the α⇒β phase transitions in CoMoO4 and NiMoO4. The Mo LII- and O K-edges in XANES are very useful for probing the local symmetry of Mo atoms in mixed-metal oxides. The results of XANES and density-functional calculations (DMo13, DFT-GGA) show large changes in the splitting of the empty Mo 4d levels when going from tetrahedral to octahedral coordinations. XANES is very useful for studying the reaction of H2, H2S and SO2 with the mixed-metal oxides. Measurements at the S K-edge allow a clear identification of S, SO2, SO3 or SO4 on the oxide surfaces. Changes in the oxidation state of molybdenum produce substantial shifts in the position of the Mo LII- and MIII-edges.

SYNTHESIS OF NOVEL NANOSTRUCTURED LANTHANUM COBALT FERRITE MIXED METAL OXIDES BY SOL–GEL

2013 ◽  
Vol 12 (01) ◽  
pp. 1350007
Author(s):  
V. MARY TERESITA ◽  
V. JESEENTHARANI ◽  
B. AVILA JOSEPHINE ◽  
S. ARUL ANTONY
Keyword(s):  
Metal Oxides ◽  
Sol Gel ◽  
Chemical Properties ◽  
Mixed Metal Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Metal ◽  
Size Dependent ◽  
Ft Ir ◽  
And Chemical Properties

Properties of nanoscale materials are very interesting and these are either comparable to or superior to those of bulk. These materials are interesting due to their exciting size dependent optical, electronic, magnetic, thermal, mechanical and chemical properties. Different mole ratios of nanostructured mixed metal oxides of LaCo x Fe 1-x O 3-δ (x = 0 to 1) were prepared by the sol–gel method by varying the mole ratios of iron and cobalt substrates. The compounds were sintered for 700°C in the tubular furnace for 8 h. The purity of the compounds was analyzed by TG-DTA. The compounds were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) studies were employed to study the structural phases, vibrational frequencies, surface morphology of the highest humidity sensing compounds.

Mesoporous mixed metal oxides derived from P123-templated Mg–Al layered double hydroxides

2010 ◽  
Vol 183 (11) ◽  
pp. 2511-2515 ◽  
Author(s):  
Jun Wang ◽  
Jideng Zhou ◽  
Zhanshuang Li ◽  
Yang He ◽  
Shuangshuang Lin ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Layered Double Hydroxides ◽  
Mixed Metal Oxides ◽  
Mixed Metal ◽  
Double Hydroxides
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