Probing ion exchange in the triflic acid-guanidinium triflate system: A solid-state nuclear magnetic resonance study

TY - JOUR

T1 - Probing ion exchange in the triflic acid-guanidinium triflate system

T2 - A solid-state nuclear magnetic resonance study

AU - Zhu, Haijin

AU - Macfarlane, Douglas

AU - Forsyth, Maria

N1 - Publisher Copyright: © 2014 American Chemical Society.

PY - 2014/12/11

Y1 - 2014/12/11

N2 - Knowledge of ion exchange and transport behavior in electrolyte materials is crucial for designing and developing novel electrolytes for electrochemical device applications such as fuel cells or batteries. In the present study, we show that, upon the addition of triflic acid (HTf) to the guanidinium triflate (GTf) solid-state matrix, several orders of magnitude enhancement in the proton conductivity can be achieved. The static 1H and 19F solid-state NMR results show that the addition of HTf has no apparent effect on local molecular mobility of the GTf matrix at room temperature. At higher temperatures, however, the HTf exhibits fast ion exchange with the GTf matrix. The exchange rate, as quantified by our continuum T2 fitting analysis, increases with increasing temperature. The activation energy for the chemical exchange process was estimated to be 58.4 kJ/mol. It is anticipated that the solid-state NMR techniques used in this study may be also applied to other organic solid-state electrolyte systems to investigate their ion-exchange processes.

AB - Knowledge of ion exchange and transport behavior in electrolyte materials is crucial for designing and developing novel electrolytes for electrochemical device applications such as fuel cells or batteries. In the present study, we show that, upon the addition of triflic acid (HTf) to the guanidinium triflate (GTf) solid-state matrix, several orders of magnitude enhancement in the proton conductivity can be achieved. The static 1H and 19F solid-state NMR results show that the addition of HTf has no apparent effect on local molecular mobility of the GTf matrix at room temperature. At higher temperatures, however, the HTf exhibits fast ion exchange with the GTf matrix. The exchange rate, as quantified by our continuum T2 fitting analysis, increases with increasing temperature. The activation energy for the chemical exchange process was estimated to be 58.4 kJ/mol. It is anticipated that the solid-state NMR techniques used in this study may be also applied to other organic solid-state electrolyte systems to investigate their ion-exchange processes.

UR - http://www.scopus.com/inward/record.url?scp=84949135618&partnerID=8YFLogxK

U2 - 10.1021/jp5101472

DO - 10.1021/jp5101472

M3 - 文章

AN - SCOPUS:84949135618

SN - 1932-7447

VL - 118

SP - 28520

EP - 28526

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 49

ER -