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Flame Hydrolysis for Oxide Supports

FIGURE 1.1 Schematic drawing of the flame hydrolysis process. [Pg.4]

Silicontetrachloride vapors are hydrolyzed in a hydrogen-oxygen flame by water vapors (Equation 1.2), which have been formed by the combustion of hydrogen in oxygen or air (Equation 1.1). The overall reaction is given in Equation 1.3. [Pg.4]

FIGURE 1.2 Average primary particle and aggregate size. [Pg.5]

Although made in an oxygen-hydrogen flame, pyrogenic alumina (AEROXIDE Alu C, Degussa) has a crystalline structure consisting of the thermodynamically metastable y- and 5-forms instead of the stable a-form [23]. The primary particle size [Pg.5]

Purity (4) Wt.% Si02 99.8 SiOj 99.8 AI2O3S99.6 Ti02 99.5 Zr02 96 [Pg.7]


Silica is the support of choice for catalysts used in processes operated at relatively low temperatures (below about 300 °C), such as hydrogenations, polymerizations or some oxidations. Its properties, such as pore size, particle size and surface area are easy to adjust to meet the specific requirements of particular applications. Compared with alumina, silica possesses lower thermal stability, and its propensity to form volatile hydroxides in steam at elevated temperatures also limits its applicability as a support. Most silica supports are made by one of two different preparation routes sol-gel precipitation to produce silica xerogels and flame hydrolysis to give so-called fumed silica. [Pg.190]


See other pages where Flame Hydrolysis for Oxide Supports is mentioned: [Pg.3]    [Pg.5]    [Pg.7]    [Pg.9]    [Pg.11]    [Pg.13]    [Pg.3]    [Pg.5]    [Pg.7]    [Pg.9]    [Pg.11]    [Pg.13]    [Pg.1498]    [Pg.81]    [Pg.167]    [Pg.52]    [Pg.1497]    [Pg.50]    [Pg.790]    [Pg.229]    [Pg.210]    [Pg.2421]    [Pg.2333]   


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Flame hydrolysis

Flame hydrolysis, oxide supports

Flame oxide

For hydrolysis

Oxidation supports

Oxidative hydrolysis

Oxide supports

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