2015
Porous Hybrid Inorganic-Organic Silicophosphate Materials by Non-Hydrolytic Sol-Gel Polycondensation and Their Use as Solid Phosphoric Acid Catalyst
STÝSKALÍK, Aleš, David ŠKODA, Zdeněk MORAVEC, Jiří PINKAS, Craig E. BARNES et. al.Základní údaje
Originální název
Porous Hybrid Inorganic-Organic Silicophosphate Materials by Non-Hydrolytic Sol-Gel Polycondensation and Their Use as Solid Phosphoric Acid Catalyst
Autoři
STÝSKALÍK, Aleš (203 Česká republika, domácí), David ŠKODA (203 Česká republika, domácí), Zdeněk MORAVEC (203 Česká republika, domácí), Jiří PINKAS (203 Česká republika, garant, domácí) a Craig E. BARNES (840 Spojené státy)
Vydání
Fourth International Conference on Hybrid Materials, 9-13 March 2015 in Sitges, Spain, 2015
Další údaje
Jazyk
angličtina
Typ výsledku
Konferenční abstrakt
Obor
10402 Inorganic and nuclear chemistry
Stát vydavatele
Španělsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Kód RIV
RIV/00216224:14310/15:00080913
Organizační jednotka
Přírodovědecká fakulta
Klíčová slova anglicky
silicophosphate xerogels; hybrid materials; heterogeneous catalysis; solid phosphoric acid
Příznaky
Mezinárodní význam
Změněno: 18. 3. 2016 18:21, prof. RNDr. Jiří Pinkas, Ph.D.
Anotace
V originále
Non-hydrolytic sol-gel reactions are viable alternatives to classical aqueous techniques in the area of synthesis of multimetallic oxides and inorganic-organic hybrid materials in the form of xerogels, nanoparticles, and thin films. We developed non-hydrolytic sol-gel route based on acetic acid ester elimination providing phosphosilicate hybrid inorganic-organic materials. The polycondensation reactions between Si(OAc)4 and OP(OSiMe3)3 lead to microporous phosphosilicate xerogels with surface areas up to 568 m2 g-1. The structure of xerogels was built up exclusively from Si-O-P bonds and contained octahedrally coordinated silicon atoms, which are characteristic for crystalline silicon phosphates.1 We changed starting precursors to acetoxysilanes and phosphonic acid esters with bridging alkyl or aryl groups (AcO)3Si-(CH2)x-Si(OAc)3 (x = 1-3, 6), (Me3SiO)2P(O)-3R-P(O)(OSiMe3)2 (3R = C2H4, C6H4). Silicon in acetoxysilanes with bridging organic groups was not able to acquire hexacoordination in contrast to Si in Si(OAc)4. The change of the structure of the xerogels, which were in this case built up from SiO4 tetrahedrons, was accompanied by the modification of textural properties – the hybrid phosphosilicates displayed significant mesoporosity. The resulting samples were chemically modified with POCl3, water and methanol in order to introduce Broensted acidic P-OH groups onto the surface of xerogels. The products of chemical modification resembled solid phosphoric acid catalysts and were utilized in methylstyrene dimerization. The mesoporous silicophosphate samples with high number of P-OH groups on the surface provided excellent yields and selectivities in this catalytic test reaction. The prepared xerogels were characterized by solid-state 13C, 29Si, 31P NMR, IR, surface area analysis, TGA and XRD.
Návaznosti
ED1.1.00/02.0068, projekt VaV |
| ||
GAP207/11/0555, projekt VaV |
| ||
LH11028, projekt VaV |
|