CsH2PO4 is not stable at 260 °C unless confined. Comments to article by C.E. Botez, I. Martinez, A. Price, H. Martinez, and J.H. Leal in J. Phys. Chem. Solids 129 (2019) 324-328

Rolf W. Berg*, Aleksey Valerievich Nikiforov, Niels J. Bjerrum

*Corresponding author for this work

Research output: Contribution to journalJournal articleCommunication

Abstract

Botez, Martinez, Price, Martinez and Leal claim in J. Phys. Chem. Solids 129 (2019) 324–328 that superprotonic CsH2PO4 (CDP) is stable in dry air at 260 °C. We discuss their observations and conclude that CDP is not stable unless sufficiently confined under a high humidity and high-pressure atmosphere, eventually formed from the sample itself. Temperature- and time-resolved impedance spectroscopy data show that a superprotonic CDP pellet measured in a hermetically sealed chamber holds a stable superprotonic conductivity of ~2×10−2 S cm−1 over a time span of 50 h at a temperature of 260 °C if the amount of sample is large enough and the container small and tight. Nyquist plots have confirmed the superprotonic nature of the conduction. X-ray diffraction data have revealed that CDP is present after the heating cycle to obtain superprotonic conductivity, but possibly CDP partly was decomposed to Cs2H2P2O7 during the heating and was reformed reacting with water during the cooling.
Original languageEnglish
Article number109177
JournalJournal of Physics and Chemistry of Solids
Volume136
Number of pages3
ISSN0022-3697
DOIs
Publication statusPublished - 2020

Keywords

  • Superconductivity
  • CsH2PO4
  • Conductivity
  • Phosphate-based electrolyte
  • High temperature

Cite this

@article{54bddb95f02945ccac9305d9e6f8c490,
title = "CsH2PO4 is not stable at 260 °C unless confined. Comments to article by C.E. Botez, I. Martinez, A. Price, H. Martinez, and J.H. Leal in J. Phys. Chem. Solids 129 (2019) 324-328",
abstract = "Botez, Martinez, Price, Martinez and Leal claim in J. Phys. Chem. Solids 129 (2019) 324–328 that superprotonic CsH2PO4 (CDP) is stable in dry air at 260 °C. We discuss their observations and conclude that CDP is not stable unless sufficiently confined under a high humidity and high-pressure atmosphere, eventually formed from the sample itself. Temperature- and time-resolved impedance spectroscopy data show that a superprotonic CDP pellet measured in a hermetically sealed chamber holds a stable superprotonic conductivity of ~2×10−2 S cm−1 over a time span of 50 h at a temperature of 260 °C if the amount of sample is large enough and the container small and tight. Nyquist plots have confirmed the superprotonic nature of the conduction. X-ray diffraction data have revealed that CDP is present after the heating cycle to obtain superprotonic conductivity, but possibly CDP partly was decomposed to Cs2H2P2O7 during the heating and was reformed reacting with water during the cooling.",
keywords = "Superconductivity, CsH2PO4, Conductivity, Phosphate-based electrolyte, High temperature",
author = "Berg, {Rolf W.} and Nikiforov, {Aleksey Valerievich} and Bjerrum, {Niels J.}",
year = "2020",
doi = "10.1016/j.jpcs.2019.109177",
language = "English",
volume = "136",
journal = "Journal of Physics and Chemistry of Solids",
issn = "0022-3697",
publisher = "Pergamon Press",

}

TY - JOUR

T1 - CsH2PO4 is not stable at 260 °C unless confined. Comments to article by C.E. Botez, I. Martinez, A. Price, H. Martinez, and J.H. Leal in J. Phys. Chem. Solids 129 (2019) 324-328

AU - Berg, Rolf W.

AU - Nikiforov, Aleksey Valerievich

AU - Bjerrum, Niels J.

PY - 2020

Y1 - 2020

N2 - Botez, Martinez, Price, Martinez and Leal claim in J. Phys. Chem. Solids 129 (2019) 324–328 that superprotonic CsH2PO4 (CDP) is stable in dry air at 260 °C. We discuss their observations and conclude that CDP is not stable unless sufficiently confined under a high humidity and high-pressure atmosphere, eventually formed from the sample itself. Temperature- and time-resolved impedance spectroscopy data show that a superprotonic CDP pellet measured in a hermetically sealed chamber holds a stable superprotonic conductivity of ~2×10−2 S cm−1 over a time span of 50 h at a temperature of 260 °C if the amount of sample is large enough and the container small and tight. Nyquist plots have confirmed the superprotonic nature of the conduction. X-ray diffraction data have revealed that CDP is present after the heating cycle to obtain superprotonic conductivity, but possibly CDP partly was decomposed to Cs2H2P2O7 during the heating and was reformed reacting with water during the cooling.

AB - Botez, Martinez, Price, Martinez and Leal claim in J. Phys. Chem. Solids 129 (2019) 324–328 that superprotonic CsH2PO4 (CDP) is stable in dry air at 260 °C. We discuss their observations and conclude that CDP is not stable unless sufficiently confined under a high humidity and high-pressure atmosphere, eventually formed from the sample itself. Temperature- and time-resolved impedance spectroscopy data show that a superprotonic CDP pellet measured in a hermetically sealed chamber holds a stable superprotonic conductivity of ~2×10−2 S cm−1 over a time span of 50 h at a temperature of 260 °C if the amount of sample is large enough and the container small and tight. Nyquist plots have confirmed the superprotonic nature of the conduction. X-ray diffraction data have revealed that CDP is present after the heating cycle to obtain superprotonic conductivity, but possibly CDP partly was decomposed to Cs2H2P2O7 during the heating and was reformed reacting with water during the cooling.

KW - Superconductivity

KW - CsH2PO4

KW - Conductivity

KW - Phosphate-based electrolyte

KW - High temperature

U2 - 10.1016/j.jpcs.2019.109177

DO - 10.1016/j.jpcs.2019.109177

M3 - Journal article

VL - 136

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

SN - 0022-3697

M1 - 109177

ER -