Catalytic activity of nanophase metals prepared sonochemically
- Univ. of Illinois, Urbana-Champaign, IL (United States)
Irradiation of liquids with high intensity ultrasound creates localized, transient hot-spots ({approx}5000 K, {approx}1700 K) with enormous heating and cooling rates (> 10{sup 9} K/sec) through the mechanism of acoustic cavitation: the formation, growth, and implosive collapse of bubbles in a liquid. This has provided us with a general route to the synthesis of nanophase clusters of metals, metal oxides, or metal carbides from the sonolysis of volatile organometallic precursors . We have prepared nanostructured powders, polymer-stabilized colloids, and silica-supported heterogeneous catalysts of metals, alloys, oxides, and carbides with typical particle sizes of {approximately}5 nm. XRPD, TEM microdiffraction, and neutron diffraction studies have established that the particles are amorphous at the manometer scale. The catalytic activity of these materials has been examined using a gas-solid flow microreactor with GC/MS detection. The sonochemically prepared Fe, Co, and Fe-Co powders are extremely active catalysts for dehydrogenation and hydrogenolysis of alkanes and for the Fischer-Tropsch hydrogenation of CO. The alloys show exceptionally high selectivity for dehydrogenation of alkanes.
- OSTI ID:
- 126514
- Report Number(s):
- CONF-950402-; TRN: 95:006086-0498
- Resource Relation:
- Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 209th ACS national meeting; PB: 2088 p.
- Country of Publication:
- United States
- Language:
- English
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