| Autor: |
Muraza, O., Rebrov, E.V., Khimyak, T., Johnson, B.F.G., Kooyman, P.J., Lafont, U., Albouy, P.A., Croon, de, M.H.J.M., Schouten, J.C. |
| Přispěvatelé: |
Chemical Reactor Engineering |
| Jazyk: |
angličtina |
| Rok vydání: |
2006 |
| Zdroj: |
Studies in Surface Science and Catalysis, 162, 167-174. Elsevier |
| ISSN: |
0167-2991 |
| Popis: |
Thin (300–1000 nm) mesoporous silica coatings with hexagonal and cubic mesostructure have been prepared on Pyrex® 7740 borosilicate glass substrates by the evaporation induced self assembly assisted sol-gel route. Prior to the synthesis, a 50 nm TiO2 layer has been deposited on the substate by atomic layer deposition from titanium tetrachloride and water to reach better adhesion of coatings to the walls of the substrate. The coatings were produced by templating a silica precursor (TEOS) with an EOxPOyEOx amphiphilic triblock copolymer (EO=ethylene oxide, PO=propylene oxide, x=106, y=70) at a pH of 2. A surfactant/silica ratio of 0.0076 was found to be optimal at a spinning rate of 1500 rpm to obtain the coatings with a surface area above 500 m2/g and a monomodal pore size distribution with a mean pore size of 6.9 nm. Mixed-metal precursor clusters [Ph4P2[Ru5PtC(CO)15 have been inserted into the mesoporous support. Then, the mesoporo-encapsulated clusters were activated by gentle heating in vacuo at 200°C. The average diameter of the resulting, well-dispersed, isolated and anchored bimetallic nanoparticles is 1.4 nm. By this approach, the functionality of the relatively fragile metallic clusters is mediated through the rigid inorganic framework providing protection and the 3D distribution of the catalytic function. The resulting coatings can be used in a number of fine chemicals synthesis reactions. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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