Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide
Elimination

a 2014

Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide Elimination

ŠKODA, David, Aleš STÝSKALÍK, Zdeněk MORAVEC, Craig E. BARNES, Jiří PINKAS et. al.

Základní údaje

Originální název

Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide Elimination

Autoři

ŠKODA, David (203 Česká republika, domácí), Aleš STÝSKALÍK (203 Česká republika, domácí), Zdeněk MORAVEC (203 Česká republika, domácí), Craig E. BARNES (840 Spojené státy) a Jiří PINKAS (203 Česká republika, garant, domácí)

Vydání

248th ACS National Meeting and Exposition, San Francisco, CA, USA, 2014

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Obor

10402 Inorganic and nuclear chemistry

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 0.269

Kód RIV

RIV/00216224:14740/14:00076458

Organizační jednotka

Středoevropský technologický institut

ISSN

Klíčová slova anglicky

Metallosilicates;Titanosilicates; Zirconosilicates; Mesoporous; Non-hydrolytic; Acetamide; Catalysis; Epoxidation

Změněno: 20. 5. 2015 20:25, Mgr. Zdeněk Moravec, Ph.D.

Anotace

V originále

Non-hydrolytic sol-gel reactions are efficient alternatives to classical aqueous techniques for synthesis of multimetallic oxides and inorganic-organic hybrid materials. This processes provides better reaction control and higher homogeneity of prepared materials. We developed nonhydrolytic sol-gel routes to several groups of metallosilicate materials based on acetamide elimination reactions. This approach is based on the condensation reaction of silicon tetraacetate Si(OAc)4 and metal amides (Ti(NEt2)4, Zr(NEt2)4). Reactions were performed at different molar ratios. Nonhydrolytic condensation leads to formation the Si–O–Ti and Si–O–Zr bonds in the xerogel framework. Diethylacetamide and acetanhydride were confirmed (GC-MS, 1H NMR) as the reaction byproducts. To achieve the mesoporous nature of the material, the reaction was successfully modified by the addition of the Pluronic P123. This copolymer has structure-directing and protecting feature and allows to prepare tough gels. After heat treatment the Pluronic P123 is burned out and xerogels are mesoporous with high surface areas. The resulting xerogels and volatile byproducts were characterized by liquid and solid-state NMR, IR, GC-MS, surface area analysis, TGA, XRD and DRUV-Vis. The catalytic activity of titanosilicate xerogels for epoxidation of cyclohexene was studied. It was found that synthesized titanosilicates are very effective catalysts for the epoxidation. The effect of titanium loading on the xerogels homogeneity was observed. The homogeneity of gels increase with the lower content of Ti. It was observed, that samples with 10 mol % of Ti contain the highest amount of four-coordinated Ti atoms. These species are the active sites of catalyst. In the case of the xerogels synthesized with Pluronic P123, the best results are achieved for calcined xerogels (500 °C). In the model epoxidation reaction the yields of cyclohexene oxide were 96 %.

Návaznosti

ED1.1.00/02.0068, projekt VaV

Název: CEITEC - central european institute of technology

EE2.3.30.0037, projekt VaV

Název: Zaměstnáním nejlepších mladých vědců k rozvoji mezinárodní spolupráce

LH11028, projekt VaV

Název: Nehydrolytické sol-gelové reakce pro přípravu křemičitanů a fosforečnanů s řízenou porozitou a funkčními skupinami na povrchu (Akronym: NHSGKNOX)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, Nehydrolytické sol-gelové reakce pro přípravu křemičitanů a fosforečnanů s řízenou porozitou a funkčními skupinami na povrchu

Citovat

ŠKODA, David, Aleš STÝSKALÍK, Zdeněk MORAVEC, Craig E. BARNES a Jiří PINKAS. Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide Elimination. In 248th ACS National Meeting and Exposition, San Francisco, CA, USA. 2014. ISSN 0009-2347.

@proceedings{1197961,
   author = {Škoda, David and Stýskalík, Aleš and Moravec, Zdeněk and Barnes, Craig E. and Pinkas, Jiří},
   booktitle = {248th ACS National Meeting and Exposition, San Francisco, CA, USA},
   keywords = {Metallosilicates;Titanosilicates; Zirconosilicates; Mesoporous; Non-hydrolytic; Acetamide; Catalysis; Epoxidation},
   language = {eng},
   title = {Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide Elimination},
   url = {http://www.acs.org/content/acs/en/meetings/fall-2014.html},
   year = {2014}
}

TY  - CONF
ID  - 1197961
AU  - Škoda, David - Stýskalík, Aleš - Moravec, Zdeněk - Barnes, Craig E. - Pinkas, Jiří
PY  - 2014
TI  - Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide Elimination
KW  - Metallosilicates;Titanosilicates
KW  - Zirconosilicates
KW  - Mesoporous
KW  - Non-hydrolytic
KW  - Acetamide
KW  - Catalysis
KW  - Epoxidation
UR  - http://www.acs.org/content/acs/en/meetings/fall-2014.html
N2  - Non-hydrolytic sol-gel reactions are efficient alternatives to classical aqueous techniques for synthesis of multimetallic oxides and inorganic-organic hybrid materials. This processes provides better reaction control and higher homogeneity of prepared materials. We developed nonhydrolytic sol-gel routes to several groups of metallosilicate materials based on acetamide elimination reactions. This approach is based on the condensation reaction of silicon tetraacetate Si(OAc)4 and metal amides (Ti(NEt2)4, Zr(NEt2)4). Reactions were performed at different molar ratios. Nonhydrolytic condensation leads to formation the Si–O–Ti and Si–O–Zr bonds in the xerogel framework. Diethylacetamide and acetanhydride were confirmed (GC-MS, 1H NMR) as the reaction byproducts. To achieve the mesoporous nature of the material, the reaction was successfully modified by the addition of the Pluronic P123. This copolymer has structure-directing and protecting feature and allows to prepare tough gels. After heat treatment the Pluronic P123 is burned out and xerogels are mesoporous with high surface areas. The resulting xerogels and volatile byproducts were characterized by liquid and solid-state NMR, IR, GC-MS, surface area analysis, TGA, XRD and DRUV-Vis. The catalytic activity of titanosilicate xerogels for epoxidation of cyclohexene was studied. It was found that synthesized titanosilicates are very effective catalysts for the epoxidation. The effect of titanium loading on the xerogels homogeneity was observed. The homogeneity of gels increase with the lower content of Ti. It was observed, that samples with 10 mol % of Ti contain the highest amount of four-coordinated Ti atoms. These species are the active sites of catalyst. In the case of the xerogels synthesized with Pluronic P123, the best results are achieved for calcined xerogels (500 °C). In the model epoxidation reaction the yields of cyclohexene oxide were 96 %.
ER  -

ŠKODA, David, Aleš STÝSKALÍK, Zdeněk MORAVEC, Craig E. BARNES a Jiří PINKAS. Mesoporous Metallosilicates Prepared by Nonhydrolytic Acetamide Elimination. In \textit{248th ACS National Meeting and Exposition, San Francisco, CA, USA}. 2014. ISSN~0009-2347.

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