Abstract: Solid heteropolyacids (HPAs) are promising nonpolluting superacids used as catalysts and solid proton conductors. The catalytic and conducting properties of HPAs are very sensitive to the amount of hydration water present in the system, as water molecules tend to interact with the HPA acid protons to form [H3O]+ and [H5O2]+ ions. These ions constitute active species that govern the catalytic reaction pathways and the proton migration mechanism. Establishing the structure and mobility of protonic species could yield important information concerning the functions of material based on HPA hydrates. In this work, we have performed the analysis of both 2H NMR line shape and the evolution of T1, T2 relaxation with temperature for the deuterated analogue of the solid 12-tungstophosphoric acid (TPA × nH2O) at different hydration levels (0 < n < 6) in the wide temperature range of 103–503 K. This allowed us to characterize in detail the mobility of different protonic species, including acidic OH groups, water molecules, and hydroxonium ions. Kinetic parameters of internal and diffusional motions for different protonic species at different hydration levels n of TPA × nH2O were derived.

Cite: Kolokolov D.I. , Kazantsev M.S. , Luzgin M.V. , Jobic H. , Stepanov A.G.
Characterization and Dynamics of the Different Protonic Species in Hydrated 12-Tungstophosphoric Acid Studied by 2H NMR
The Journal of Physical Chemistry C. 2014. V.118. N51. P.30023-30033. DOI: 10.1021/jp510410k WOS Scopus РИНЦ ANCAN OpenAlex

Dates:

Submitted:	Oct 16, 2014
Accepted:	Nov 25, 2014
Published online:	Dec 11, 2014
Published print:	Dec 26, 2014

Identifiers:

Web of science:	WOS:000347360200064
Scopus:	2-s2.0-84920059252
Elibrary:	24026317
Chemical Abstracts:	2014:2011691
Chemical Abstracts (print):	162:114660
OpenAlex:	W2326229220

Citing:

DB	Citing
Web of science	24
Scopus	26
Elibrary	25
OpenAlex	25

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