Chemical and Electrochemical Behavior in Molten Alkali Hydroxides: III . Chemistry of Tin (II) and (IV) in the Eutectic Mixture and in Pure

Abstract

This paper describes the chemical behavior of tin (II) and (IV) in the eutectic mixture normalNaOH‐KOH (49M%) at 483 K and in molten normalNaOH at 623 K. Sn(II) is unstable in molten hydroxides and is oxidized by the solvent. The oxidation of normalSnO occurs either directly in the solid phase or after dissolution as SnO22− . Basic conditions promote the liquid phase oxidation. Sn(IV) dissolves as SnO32− in the eutectic mixture. Soluble in basic melts, it is only slightly soluble in acidic melts and precipitates as Na2SnO3 false(normals=6.8+0.6×10−4Mfalse) at water concentrations <4.10−2 M and as a mixture of SnO2 and Na2SnO3 in more acidic media. Sn(IV) is practically insoluble in acidic sodium hydroxide false(normals<10−6Mfalse) and precipitates as Na2SnO3 . It dissolves in basic melts as SnO44− false(s<10−3Mfalse) , Na4SnO4 being precipitated from saturated solutions.

Reduction in Formation Temperature of Ta-Doped Lithium Lanthanum Zirconate by Application of Lux–Flood Basic Molten Salt Synthesis

“…On the basis of these results, we conclude that all three flux components are important to efficiently form LLZTO in the case of HB-MSS. There appears to be a synergistic effect of these three components that results in the effectiveness of the HB-MSS method, wherein the relatively low melting point of LiNO 3 (∼264 °C) 44 helps to reduce the melting point of the mixture, LiOH acts as an amphoteric solvent, 51 and Li 2 O 2 acts as a base, liberating reactive oxygen species as it decomposes 52 starting around 250 °C, while also forming reactive Li 2 O.…”