Mesoporous templated silicates: an overview of their synthesis, catalytic activation and evaluation of the stability

Linssen, Thierry; Cassiers, Kristof; Cool, Pegie; Vansant, Etienne F.

doi:10.1016/s0001-8686(02)00084-2

Cited by 187 publications

(183 citation statements)

References 181 publications

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…In the synthesis of MS-3, the gel pH was measured to be 2.1, which is close to the theoretical isoelectric point of silica (pHE2) [5]. Under this condition, the steady-state condensation of SiO À decreased, and the reaction step became rate-limiting.…”

Section: Article In Presssupporting

confidence: 60%

“…Under the moderate acid concentration in the synthesis of MS-1 and MS-2, the condensation of the silica oligomers was faster than the hydrolysis of TEOS. This was due to the strong nucleophilicity of the deprotonated silanol (SiO À ), which favors the condensation process [5]. As a result, the mesopore channels did not satisfactorily form, because the silicate oligomers tended to undergo condensation, which limited their opportunity to assemble themselves into mesoscopic channels.…”

Section: Effect Of Tcp Contentmentioning

confidence: 99%

“…The most commonly used surfactant for mesoporous silica synthesis is poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), or EO n -PO m -EO n , with various m and n values [5]. The successful synthesis of SBA-15 has been reported using EO 20 -PO 70 -EO 20 , whereas the use of EO 106 -PO 70 -EO 106 results in cubic SBA-16 [6].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Elucidation of interactive effects of synthesis conditions on the characteristics of mesoporous silicas templated using polyoxide surfactant

Abdullah

Kamaruddin

Razali

et al. 2007

Science and Technology of Advanced Materials

View full text Add to dashboard Cite

A series of mesoporous silicas (MS-1-MS-9) were synthesized at different gel compositions using a triblock copolymer (TCP), poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), as the surfactant. The interactive effects of acidity, the contents of tetraethyl orthosilicate (TEOS) and the surfactant, and the gelling temperature on the characteristics of the final material were simultaneously characterized. Increasing acidity favored mesopore formation. A material with a surface area of 760 m 2 /g, mostly in the mesoporous range, was obtained at 1.0(TEOS):0.017(TCP):7.3HCl:115.7H 2 O. Mesopore formation was predominantly determined by the TEOS:TCP ratio and was promoted with its increase from 1.56:1 to 2.09:1. A further increase to 2.61:1 was detrimental. Whereas increasing the TCP content to 3.5% w/w improved micellization, a further increase to 4.6% should be avoided. Mesoporous silicas showed low crystallinity but a high degree of hexagonal mesoscopic organization. The weak surface acidity was attributed to surface silanols, the number of which was proportional to mesoporosity. r

show abstract

Section: Article In Presssupporting

confidence: 60%

Section: Effect Of Tcp Contentmentioning

confidence: 99%

See 1 more Smart Citation

Elucidation of interactive effects of synthesis conditions on the characteristics of mesoporous silicas templated using polyoxide surfactant

Abdullah

Kamaruddin

Razali

et al. 2007

Science and Technology of Advanced Materials

View full text Add to dashboard Cite

show abstract

“…Otherwise, the formation of silica aggregates in the interlayer region would depend only on the clay: silica relationship [24]. One of the main advantages of using PCHs compared to other materials such as pillared clays is that the density of the interspaced material is controlled by the mounting mechanism, whatever the initial amount of silica [25].…”

Section: LImentioning

confidence: 99%

Porous heterostructured clays - recent advances and challenges - revisão

Schwanke

Pergher

2013

Cerâmica

View full text Add to dashboard Cite

Porous heterostructured clays -PCHs -are lamellar solids with acid and adsorptive properties serving as catalysts or catalyst supports formed on a template mechanism. This work provides information about porous heterostructured clays. Historical aspects of the development of lamellar solids to porous heterostructured clays will be discussed, and detailed information on synthesis and applicationaspects, as well as on the infl uence of eachreagent on these materials and the characterization techniques used to prove their formation will be given. Keywords: porous heterostructured clays, PCHs, lamellar solids. Resumo Argilas porosas heteroestruturadas -PCHs -são sólidos lamelares com propriedades ácidas e adsortivas que servem de catalisadores ou suporte de catalisadores formados pelo mecanismo de gabarito. O presente trabalho traz informações sobre as argilas porosas heteroestruturadas -PCHs. Aspectos históricos sobre o desenvolvimento dos materiais lamelares até osPCHs são abordados, bem como informações detalhadas sobre aspectos de síntese, aplicações, a infl uência de cada reagente na formação destes materiais e as técnicas de caracterização essenciais utilizadas para comprovar a sua formação. Palavras-chave: argilas porosas heteroestruturadas, PCHs, sólidos lamelares.Cerâmica 59 (2013) 576-587

show abstract

“…Up to now, MMS with pores of sizes ranging from 2 to 30 nm have been developed [3], and are being examined for their catalytic applicability in variable chemical reactions [4,5]. However, the general catalytic processes involve hot water or high temperature conditions, which makes the structure of MMS very weak and unstable due to the hydrolysis of the Si-O-Si bonds and the thin pore walls.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Thermally Stable MCM-41 Mesostructure Using Ethylamine

Lee¹,

Ahn

Kim³

2004

Resources Processing

View full text Add to dashboard Cite

Ethylamine(EA) was used as an additive instead of mineralizers such as NaOH and TPAOH to synthesize MCM-41 molecular sieves with high structural stability and long range order. Small angle X-ray diffraction showed that the EA/CTAB (cetyltrimethylammonium bromide) ratio was the critical factor that determines the degree of ordering in MCM-41. The samples had walls approximately 2 nm thick, which is the thickest level ever reported. Therefore, they did not lose their structure entirely even after heat treatment at 1000°C. Together with the effect of the EA/CTAB ratio, the textural mesoporosity, as confirmed from the N2 adsorption-desorption isotherm analysis, suggests the EA participates in the templating process of the mesostructure. In addition, the decrease of the lattice parameter and the pore size with increasing EA concentration implies the role of EA as co-surfactant.

show abstract

Mesoporous templated silicates: an overview of their synthesis, catalytic activation and evaluation of the stability

Cited by 187 publications

References 181 publications

Elucidation of interactive effects of synthesis conditions on the characteristics of mesoporous silicas templated using polyoxide surfactant

Elucidation of interactive effects of synthesis conditions on the characteristics of mesoporous silicas templated using polyoxide surfactant

Porous heterostructured clays - recent advances and challenges - revisão

Preparation of Thermally Stable MCM-41 Mesostructure Using Ethylamine

Contact Info

Product

Resources

About