Phase Transformation Dynamics in Sulfate-Loaded Lanthanide Triphosphonates. Proton Conductivity and Application as Fillers in PEMFCs.

ABSTRACT: Phase transformation dynamics and proton conduction properties are reported for cationic layer-featured coordination polymers derived from the combination of lanthanide ions (Ln³⁺) with nitrilo-tris(methylenephosphonic acid) (H₆NMP) in the presence of sulfate ions. Two families of materials are isolated and structurally characterized, i.e., [Ln₂(H₄NMP)₂(H₂O)₄](HSO₄)₂·nH₂O (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Er, Yb; n = 4-5, Series I) and [Ln(H₅NMP)]SO₄·2H₂O (Ln = Pr, Nd, Eu, Gd, Tb; Series II). Eu/Tb bimetallic solid solutions are also prepared for photoluminescence studies. Members of families I and II display high proton conductivity (10^-3 and 10^-2 S·cm^-1 at 80 °C and 95% relative humidity) and are studied as fillers for Nafion-based composite membranes in PEMFCs, under operating conditions. Composite membranes exhibit higher power and current densities than the pristine Nafion membrane working in the range of 70-90 °C and 100% relative humidity and with similar proton conductivity.

SUBMITTER: Salcedo IR 

PROVIDER: S-EPMC8610370 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature