화학공학소재연구정보센터
Inorganic Chemistry, Vol.56, No.22, 13949-13954, 2017
Formation of Amorphous H3Zr2Si2PO12 by Electrochemical Substitution of Sodium Ions in Na3Zr2Si2PO12 with Protons
The Sodium ions in Na3Zr2Si2PO12(NASTCON) were substituted with protons Using an electrochemical alkali-proton substitution (APS) technique at 400 degrees C under a 5% H-2/95% N-2 atmosphere. The sodium ions in NASICON were successfully substituted with proton to a depth,of <400 mu m from the anode. Completely protonated-NASICON, i.e., H3Zr2Si2PO12, was obtained to la depth <40 mu m from the, anode, although complete protoriation of NASICON cannot be achieved by ion exchange in aqueous acid H3Zr2Si2PO12 was amorphous, whereas the partially protonated NASICON was crystalline, and its unit cell volume decreased with an increase in the extent of substitution. Amorphous H3Zr2Si2PO12 was prepared by pressure-induced amorphization of the NASICON framework, in which an internal pressure of similar to 3.5 GPa was induced by the substitution of large sodium ions with small protons during APS at 400 degrees C.