Easy and effective synthesis of micrometer-sized rectangular MgO sheets with very high catalytic activity

Selvamani, Thangavel; Yagyu, Takeyoshi; Kawasaki, Shigeo; Mukhopadhyay, Indrajit

doi:10.1016/j.catcom.2009.12.014

Cited by 78 publications

(51 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Increasing amounts of Mg(OH) 2 in samples M1, M2 and M3 is observed. This is because at this temperature, Mg(OH) 2 can be formed as a secondary phase. Therefore, when the precursor is heated and the annealing time is increased, more Mg(OH) 2 will be formed.…”

Section: Resultsmentioning

confidence: 99%

“…2 on the high quality datasets where crystal structural parameters such as lattice constants, unit cell volume, site occupancy factors and others are obtained as listed in Table I. Samples M1 to M3 show presence of a secondary phase, Mg(OH) 2 , and the amounts are given in Table I. The other samples are all phase pure of the cubic FCC crystal structure with Fm-3m space group.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, when the precursor is heated and the annealing time is increased, more Mg(OH) 2 will be formed. However, Mg(OH) 2 can be decomposed to MgO but the reaction of course happens a little later, that is, after its formation such that when the annealing time is 5 h, it is observed that all of the Mg(OH) 2 have decomposed and disappeared from the sample leaving just the stable MgO in its cubic phase.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] These novel characteristics depend on the shape and size of the nanomaterials. 1 As the particle dimensions of the nanomaterials reduce to that of less than 100 nm, quantum mechanical effects will manifest themselves and become more observable.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Band Gap Narrowing of 2-D Ultra-Thin MgO Graphene-Like Sheets

Kamarulzaman

Chayed

Badar

et al. 2016

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

Ultra-thin MgO nanosheets obtained by a sol-gel method were found to have cubic crystal structure with a space group of Fm-3m. The thickness of the sheets for the 600°C and 5 h annealing condition sample is 2 nm. Although the MgO sheets are two-dimensional and ultra-thin, unlike graphene, they are polycrystalline. Their bandgap energies are dependent on the thermal annealing conditions (which affect the thickness of the MgO nanosheets). It is found that there was bandgap narrowing of the MgO nanosheets with respect to the bulk values. UV-visible spectroscopy and X-Ray Photoelectron spectroscopy (XPS) enables us to identify the shifts of the valence and conduction bands causing the bandgap narrowing.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Band Gap Narrowing of 2-D Ultra-Thin MgO Graphene-Like Sheets

Kamarulzaman

Chayed

Badar

et al. 2016

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…[36] This poor performance has driven the development of new MgO architectures and presentation formats which afford higher surface areas in an attempt to improve its reactivity towards various catalytic processes. [37][38][39] Although the general consensus is that the efficacy of solid base catalysts in triglyceride transesterification is favoured by stronger basic sites at the catalyst surface, [34,40] the influence of surface basicity upon catalytic activity remains poorly understood, hampering further catalyst optimisation and the commercial exploitation of MgO in biodiesel production. [66] and formic acid [66] at room temperature.…”

Section: Methodsmentioning

confidence: 99%

The surface chemistry of nanocrystalline MgO catalysts for FAME production: An in situ XPS study of H2O, CH3OH and CH3OAc adsorption

et al. 2016

View full text Add to dashboard Cite

An in situ XPS study of water, methanol and methyl acetate adsorption over as-synthesised and calcined MgO nanocatalysts is reported with a view to gaining insight into the surface adsorption of key components relevant to fatty acid methyl esters (biodiesel) production during the transesterification of triglycerides with methanol. High temperature calcined NanoMgO-700 adsorbed all three species more readily than the parent material due to the higher density of electron-rich (111) and (110) facets exposed over the larger crystallites. Water and methanol chemisorb over the NanoMgO-700 through the conversion of surface O 2-sites to OH -and coincident creation of Mg-OH or Mg-OCH3 moieties respectively. A model is proposed in which the dissociative chemisorption of methanol occurs preferentially over defect and edge sites of NanoMgO-700, with higher methanol coverages resulting in physisorption over weakly basic (100) facets. Methyl acetate undergoes more complex surface chemistry over NanoMgO-700, with C-H dissociation and ester cleavage forming surface hydroxyl and acetate species even at extremely low coverages, indicative of preferential adsorption at defects.Comparison of C 1s spectra with spent catalysts from tributyrin transesterification suggest that ester hydrolysis plays a key factor in the deactivation of MgO catalysts for biodiesel production.

show abstract

Hydromagnesite as an Efficient Recyclable Heterogeneous Solid Base Catalyst for the Synthesis of Flavanones, Flavonols and 1,4‐Dihydropyridines in Water

2013

View full text Add to dashboard Cite

A form of hydromagnesite (HM) with flower‐like thin‐sheet morphology was synthesized by an environmentally benign approach using simple conventional heating at moderate temperature without using any template in water as medium. The versatility of this HM catalyst was studied in the synthesis of flavanones, flavonols and the multicomponent synthesis of 1,4‐dihydropyridines in water. The recyclability of catalyst was studied for six times and there was no appreciable loss in its catalytic activity.magnified image

show abstract

Easy and effective synthesis of micrometer-sized rectangular MgO sheets with very high catalytic activity

Cited by 78 publications

References 32 publications

Band Gap Narrowing of 2-D Ultra-Thin MgO Graphene-Like Sheets

Band Gap Narrowing of 2-D Ultra-Thin MgO Graphene-Like Sheets

The surface chemistry of nanocrystalline MgO catalysts for FAME production: An in situ XPS study of H2O, CH3OH and CH3OAc adsorption

Hydromagnesite as an Efficient Recyclable Heterogeneous Solid Base Catalyst for the Synthesis of Flavanones, Flavonols and 1,4‐Dihydropyridines in Water

Contact Info

Product

Resources

About