Characterization of mechanochemically synthesized MHSO4–H4SiW12O40 composites (M=K, NH4, Cs)

• Published in: Materials research bulletin Vol. 47; no. 10; pp. 2931 - 2935
• Main Authors: Oh, Song-yul, Kawai, Keisuke, Kawamura, Go, Muto, Hiroyuki, Matsuda, Atsunori
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2012
• Subjects: Ambient pressure; Anhydrous proton conductivity; H4SiW12O40; Mechanochemical synthesis; MHSO4; MHSO4; H4SiW12O40; Anhydrous proton conductivity; Ambient pressure; Mechanochemical synthesis
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2012.04.051

► Mechanochemical synthesis of various MHSO4–H4SiW12O40 (MHS–STA, M=K, NH4, Cs) composites as an electrolyte. ► Anhydrous proton conductive electrolytes under ambient pressure for fuel cells. ► Chemical interaction via ion-exchange and hydrogen bond between MHS and STA. Anhydrous proton conductive MHSO4–H4SiW12O40 (MHS–STA) composites were successfully synthesized using mechanochemical treatment. 80MHS·20STA (mol%) composite, for example, showed very high anhydrous proton conductivity above 10−3Scm−1 in a temperature range from 160 to 60°C under ambient pressure. From the X-ray diffraction study, it was confirmed that the mechanochemical treatment induced chemical interactions via ion-exchange between M+ ion in MHS and H+ ion in STA. Furthermore, phase-transition of raw substances, such as melting, dehydration and superprotic phase-transition, was suppressed in mechanochemically synthesized MHS–STA composites, indicating that improvement of anhydrous proton conductivity for MHS–STA composites is caused by the changes in protic conduction behavior.