Building Block approach to SiO2–ZrO2 porous materials

✍ Scribed by Isao Hasegawa; Kyoko Hibino; Kohichi Takei

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 71 KB
• Volume: 13
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/(sici)1099-0739(199908)13:8<549::aid-aoc890>3.0.co;2-5

✦ Synopsis

2-Hydroxyethyl)trimethylammonium silicate, Si 8 O 20 [N(CH 3 ) 3 (C 2 H 4 OH)] 8 ÁnH 2 O, was allowed to react with zirconium tetrakis(2,4-pentanedionate) in methanol, resulting in gel formation. The gels were heat-treated at 650-1000 °C in air.

The product at 650 °C showed a specific surface area of 500 m 2 g À1 , and the average pore diameter was ca 4.3 nm, indicating the formation of a thermally stable mesoporous body. Gels with the same composition were also prepared by sol-gel processing using tetraethoxysilane as a silica source. The specific surface area of the product yielded by heating the gels at 650 °C was 425 m 2 g À1 and the average pore diameter was ca 2.8 nm, which were lower than those of the product from the gels prepared with (2-hydroxyethyl)trimethylammonium silicate. These differences have been attributed to the difference in nanostructure of the gels, caused by the structure of the silica sources and their polymerization behaviour.