Results 1 - 10 of 41394
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[en] The successful preparation of a macroscopic sample of enriched 33S by laser-induced molecular dissociation is reported. Approach was to induce isotopically selective dissociation of SF6 with CO2-laser pulses and to separate the remaining SF6 from the sulfur-containing reaction products by cryogenic distillation. A 200 Hz, 0.75 J/pulse laser was used for photolysis of low-pressure (less than 1 torr) gas mixtures. The mixture of SF6 and scavenger recirculated continuously throughout the irradiation chamber where the laser pulses selectively dissociated 32SF6 to give the final products: SF4 or SOF2. The unreacted SF6 was enriched in the heavier isotopes: 33S, 34S, and 36S. A 1.3-g sample of SF6 was collected with a 33S enrichment factor of 1.96 and a 34S enrichment factor of 2.25. A similar size sample of depleted (32S) sulfur compounds was also collected. A scavenger was necessary to ensure high yield, and moist hydrogen was found to be best for our conditions. Removal of hydrogen fluoride was also necessary to prevent severe corrosion and to maintain high isotopic selectivity. 6 figures
[en] Isotopically selective reactions of SF5Cl have been induced by intense CO2 laser radiation at frequencies near the sulfur-fluorine stretching fequency ν8 at 909 cm-1. The experiments were performed at low pressure (0.25 to 4.0 torr) with neat SF5Cl and several SF5Cl-diluent mixtures. The reaction yield, product distribution, and isotopic selectivity were determined for various reaction conditions. A reaction mechanism was proposed with simple sulfur-chlorine bond cleavage being the primary photolytic reaction
[en] The laser-induced multiphoton excitation is a selective, direct method for decomposing small polyatomic molecules. Most informative example of the effect is the separation of sulfur isotopes in SF6. The understanding of the non-linear photon absorption process, for which there is no satisfactory theoretical description as yet, is of special interest. (author)
[en] SO_2-depolarized electrolysis (SDE) is the pivotal reaction in hybrid sulfur process. To date, the total cell potential for an SO_2-depolarized electrolyzer has been identified to be controlled dominantly by the sulfuric acid concentration of the anolyte and electrolysis temperature. Potential loss in SDE can be separated into four components, i.e., equilibrium potential, anodic polarization overpotential, cathodic polarization overpotential, and ohmic loss. In this work, the potential individual components of SDE were measured and calculated. Results showed that the anodic polarization overpotential exhibited the highest ratio in the cell voltage of SDE reaction, and the kinetics of the anodic reaction was controlled by a distinct reaction process under different cell potentials. This study increases understanding on SDE and provides assistance to improve its performance.