Sharpless Laurel, Moon Jeremy, Chidambaram Dev
Chemical and Materials Engineering, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557-0388, United States.
Nevada Institute for Sustainability, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States.
J Phys Chem Lett. 2024 May 23;15(20):5529-5534. doi: 10.1021/acs.jpclett.4c00930. Epub 2024 May 16.
Currently, there is a lack of reliable measurement techniques for understanding the basicity of molten chloride salts. Optical basicity, an ultraviolet-visible (UV-vis) spectroscopic method for measuring Lewis basicity, is explored for its applicability to molten chloride salts. Shifts in probe ion (Pb and Bi) electronic transitions are observed that show that cations in chloride salts follow the same basicity series as in oxide melts, and an increase in basicity is observed with increasing temperature. Pb and Bi are validated as effective probe ions in alkali, alkaline earth, and aluminum-sodium chloride molten salts. However, the utility of Bi is limited by the volatility of BiCl at high temperatures, posing a challenge for use in high-temperature molten salt applications. Since optical basicity measures the extent of electron donation, it may be a useful metric for electrochemical corrosion.
