The effect of cation substitution on the local coordination of protons in Ba2In1.85M0.15O6H2 (M = In, Ga, Sc and Y)
Journal article, 2021

We report on an investigation of the local structure and vibrational dynamics in the brownmillerite-based proton conductors Ba2In1.85M0.15O6H2 with M = In, Ga, Sc and Y. The aim is to determine the effect of the cation (M) substitution on the local coordination environment of the protons. The techniques used are infrared spectroscopy and inelastic neutron scattering. The materials are characterized by two main types of proton sites, denoted as H (1) and H(2), which are featured by different local structures. We establish that the relative population of these two proton sites varies as a function of M. Specifically, it is found that, with respect to Ba2In2O6H2, the relative population of H(1) protons increases upon the substitution of In with any of the three different cations. The strongest effect is observed for M = Ga and Sc, whereas the effect observed for M = Y is minor. This new insight motivates efforts to unravel the mobility of the two types of protons, since then cation modification would offer a rational route for improving the proton conductivity of these types of materials.

Brownmillerite-based oxides

Cation substitution

Local structure

Vibrational spectroscopy

Proton sites

Author

Laura Mazzei

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Fabio Piccinelli

Verona University

Marco Bettinelli

Verona University

Stewart F. Parker

STFC Rutherford Appleton Laboratory

Maths Karlsson

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Solid State Ionics

0167-2738 (ISSN)

Vol. 365 115624

New insights in hydrogenous materials for energy

Swedish Research Council (VR) (621-2010-3519), 2011-01-01 -- 2016-12-31.

Swedish Research Council (VR) (621-2010-3519), 2011-01-01 -- 2016-12-31.

Subject Categories

Inorganic Chemistry

Ceramics

Theoretical Chemistry

DOI

10.1016/j.ssi.2021.115624

More information

Latest update

6/29/2021