Synthesis and characterization of Fe and FeS{sub 2} (pyrite) catalyst particles in inverse micelles
Stock solutions of 10 wt. % surfactant are prepared in various organic solvents to produce the inverse micelle solutions. The iron salts are added directly to prepare 0.001--0.01M solutions, and are mixed overnight on a stirring plate to assure complete solubilization. Concentrated aqueous cadmium chloride solutions are mixed with the stock inverse micelles solutions to prepare 0.0005--0.M cadmium chloride microemulsions. To reduce the iron salts, the concentrated LiBH{sub 4}/THF solution is injected into the inverse micelle solutions under rapid stirring. To sulfide the iron and cadmium salts, the Li{sub 2}S/H{sub 2}0 solution is injected into the inverse micelle or microemulsion solutions under rapid stirring. The reaction is carried out and the final product is stored under dry, oxygen-free conditions. The reducing agent or sulfiding agent is added in an excess molar concentration to favor the formation of the surfactant stabilized sols. The inverse micelle and cluster solutions are studied by small angle neutron scattering (SANS), UV-visible spectrophotometry, and electron microscopy (TEM). SANS is carried out at the Low-Q Diffractometer at the Los Alamos Neutron Scattering Center. Deuterated organic solvents are used. The inverse micelle radius of gyration is determined by Guinier analysis of the scattering curve [7]: I = N exp(-q{sup 2}R{sub g}{sup 2/3}), where N is a proportionality constant, q is the scattering vector, and R{sub g} is the radius of gyration-of the inverse micelles. UV-visible spectrophotometry of the particle solutions is completed in-situ with a Hewlett Packard 8452A diode array spectrophotometer. Relative size and characterization of the particles is achieved through analysis of the plasmon resonances observed in metal particles and the band gap structure observed in semiconductors. Finally, TEM using a Joel 1200EX sizes the particles and selected area electron diffraction aids in the particle characterization.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 10142203
- Report Number(s):
- SAND-93-0072C; CONF-930304-11; ON: DE93009632
- Resource Relation:
- Conference: 205. American Chemical Society national meeting,Denver, CO (United States),28 Mar - 2 Apr 1993; Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
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Synthesis and characterization of Fe colloid catalysts in inverse micelle solutions
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