Ba3-xKxHx(PO4)2: Synthesis and properties of a new class of solid state proton conductors

Calum R I Chisholm*, Sossina M. Haile

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review


Compounds with the general formula (M+13H(XO4), M = Cs, Rb, NH4 and X = S, Se undergo superprotonic transitions to trigonal structures with very high protonic conductivity (∼ 10-2/ω-cm), making them very appealing as solid state electrolytes in fuel cell. These compounds are reduced when used as fuel cell electrolytes. Phosphate analogs exist, with general formula M+23(PO4)2), which exhibit nearly identical trigonal structures. Moreover, the superprotonic phosphate CsH2PO4 had been stable under fuel cell operational conditions. Compounds with stoichiometry Ba+23-xK+1xHx(PO 4)2, x = 0-1, were synthesized to combine the trigonal structure and chemical stablity of Ba3(PO4)2 with the superprotonic conductivity of the M+13H(XO4) compounds. The protonic conductivity of the Ba+23-xK+1xHx(PO 4)2 compounds increased by 1000 times compared to that of Ba3(PO4). However, the level of conductivity was still 100 times less than that expected for a superprotonic phase due to local order within the structure. This is an abstract of a paper presented at the 229th ACS National Meeting (San Diego, CA 3/13-17/2005).

Original languageEnglish (US)
Pages (from-to)INOR-451
JournalACS National Meeting Book of Abstracts
Issue number1
StatePublished - 2005
Event229th ACS National Meeting - San Diego, CA., United States
Duration: Mar 13 2005Mar 17 2005

ASJC Scopus subject areas

  • General Chemistry
  • General Chemical Engineering


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