Abstract:

Aiming to address the unclear reaction mechanisms of trace impurities in electron-grade hydrofluoric acid， this study focuses on fluoromanganate-like metal complexes. The reaction pathways of trace impurity manganese（Mn） and other metal impurity ions（sodium ［Na⁺］， calcium ［Ca²⁺］， and aluminum ［Al³⁺］， representing typical mono-， di-， and tri-valent impurity ions） within the hydrofluoric acid system were investigated through density functional theory（DFT） calculations. By DFT combined with analyses of electrostatic charge distributions， differential charge density and binding energy calculations， the stability of the reaction products（AlMnF₈， CaMnF₆， NaMnF₆） and their potential for separation from hydrofluoric acid（HF） were revealed. The results show that AlMnF₈， generated by the reaction of Al³⁺ with Mn， has the lowest total system energy（-30.878 eV） and the most stable structure； the binding energy analysis further confirms that the absolute value of the binding energy of AlMnF₈ with HF（0.488 eV） is lower than that of NaMnF₆（0.758 eV） and CaMnF₆（0.798 eV）， which suggests that it can be more easily detached from HF solution by physical separation. This study provides a theoretical basis for the efficient removal of trace manganese complexes in electronic grade HF.

Key words: Electronic grade hydrofluoric acid, Density functional theory calculation, Fluoromanganate, Trace impurity removal