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Molten chlorides are proposed for fast-spectrum molten salt reactors. Molten MgCl 2 with NaCl forms eutectic mixtures and is considered as a promising dilutant to dissolve fuel salts such as UCl 3 and UCl 4 . A previous study suggests the formation of a U-Cl network at the U : Na=1 : 1 binary salt. However, it is unclear how the structure of UCl n (n=3, 4) in NaCl will change after adding MgCl 2 in the salt. Here, we use first-principles molecular dynamics to investigate the molten ternary salts NaCl-MgCl 2 -UCl n (n=3, 4) at various concentrations of Mg 2+ in NaCl-UCl n with a fixed ratio of Na : U at 1 : 1. It is found that the addition of Mg 2+ to NaCl-UCl 3 leads to a higher coordination number (from 6.5 to 6.7) of Cl around U while the U-Cl network structure slightly decreases with the Mg concentration. Adding MgCl 2 to NaCl-UCl 4 , however, breaks down the U-Cl network more completely. We attribute the different behavior of adding Mg 2+ into NaCl-UCl 3 and NaCl-UCl 4 to the difference between U(III) and U(IV) in attracting Cl - ions to form the first coordination shell. The present work reveals the impact of MgCl 2 as a dilutant solvent for NaCl-UCl n fuel salts, which will be helpful in further studies and understanding of the thermophysical and transport properties of ternary systems., (© 2022 Wiley-VCH GmbH.)

We developed a molten salts process to prepare Co 9 S 8 nanoparticles (NPs) entrapped, S, N co-doped carbons. Cobalt chloride was used as the cobalt source. The melamine-formaldehyde (MF) resin provided the carbon source and nitrogen source, and thiourea provided sulfur source. In addition, common inorganic salts were added as templates to generate pores. The characterization results showed that the prepared materials contained high contents of N, S and Co, and were mesoporous composites. At the same time, the porosity of electrocatalyst depended on the type of salt and the mass ratio of precursor to salt, which further affected the electrocatalytic activity of hydrogen evolution reaction (HER). The best prepared catalyst showed excellent HER performance. The onset overpotential of the catalyst was low (33 mV) and had a small Tafel slope (61.1 mV dec -1 ), in addition to good stability in alkaline media., (© 2022 Wiley-VCH GmbH.)

Nanofluids have great potential in a wide range of fields including solar thermal applications, where molten salt nanofluids have shown great potential as a heat transfer fluid (HTF) for use in high temperature solar applications. However, no study has investigated the use of molten salt nanofluids as the HTF in direct absorption solar collector systems (DAC). In this study, a two dimensional CFD model of a direct absorption high temperature molten salt nanofluid concentrating solar receiver has been developed to investigate the effects design and operating variables on receiver performance. It has been found that the Carnot efficiency increases with increasing receiver length, solar concentration, increasing height and decreasing inlet velocity. When coupled to a power generation cycle, it is predicted that total system efficiency can exceed 40% when solar concentrations are greater than 100×. To impart more emphasis on the temperature rise of the receiver, an adjusted Carnot efficiency has been used in conjunction with the upper temperature limit of the nanofluid. The adjusted total efficiency also resulted in a peak efficiency for solar concentration, which decreased with decreasing volume fraction, implying that each receiver configuration has an optimal solar concentration.

We herein describe a straight forward procedure to increase the performance of platinum-on-alumina catalysts in methanol steam reforming by applying an alkali hydroxide coating according to the "solid catalyst with ionic liquid layer" (SCILL) approach. We demonstrate by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption (TPD) studies that potassium doping plays an important role in the catalyst activation. Moreover, the hygroscopic nature and the basicity of the salt modification contribute to the considerable enhancement in catalytic performance. During reaction, a partly liquid film of alkali hydroxides/carbonates forms on the catalyst/alumina surface, thus significantly enhancing the availability of water at the catalytically active sites. Too high catalyst pore fillings with salt introduce a considerable mass transfer barrier into the system as indicated by kinetic studies. Thus, the optimum interplay between beneficial catalyst modification and detrimental mass transfer effects had to be identified and was found on the applied platinum-on-alumina catalyst at KOH loadings around 7.5 mass%., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The most advanced methodology for the pyroprocessing of spent nuclear fuel is the electrorefining of uranium metal in LiCl-KCl eutectic, in which uranium is solubilized as U(III). The production of U(III) in LiCl-KCl eutectic by the chlorination of uranium metal using BiCl3 has been performed for research purposes. In this work, this reaction was studied in-situ by visual observation, electronic absorption spectroscopy and electrochemistry at 450 °C. The most likely mechanism has been determined to involve the initial direct oxidation of uranium metal by Bi(III) to U(IV). The dissolved U(IV) then reacts with unreacted uranium metal to form U(III). [ABSTRACT FROM AUTHOR]

Corrosion tests of 316 stainless steel (316SS) in NaCl–KCl–NaF reciprocal salts were conducted at different temperatures. Results showed that the reciprocal salts had perfect compatibility with 316SS even without special treatment, and a stable Cr–O enriched layer was first observed. The stabilization mechanism of chromium oxides in molten salts was explored, where the low oxoacidity was conducive to from the stable chromium oxides. These findings can provide a new direction for the design and corrosion control of molten salts. • Corrosion behavior of 316SS in NaCl-KCl-NaF salts was studied at high temperature. • NaCl-KCl-NaF salts had perfect compatibility with 316SS without special treatment. • Corrosion zone of three-layer structure and stable protective layer were observed. • Stabilization mechanism of Cr oxides protective layer in molten salts was explored. [ABSTRACT FROM AUTHOR]