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.
Highlights
Up to now, Nafion has been the benchmark of polymer electrolytes
Preliminary studies show that the resulting composite membranes exhibit similar proton conductivity behavior and, in some cases, higher power and current densities than the pristine Nafion membrane working in the range of 70−90 °C and 100% RH
The crystal structure of the sulfate-deficient derivative, SDLn-I, has been reported elsewhere,[41] and here, we report the crystallographic data for Tb3+ derivative (SD-Tb-I), from Rietveld refinement (Table 1, Figure S18)
Summary
Nafion has been the benchmark of polymer electrolytes. new advances are desirable to facilitate enhanced performance for proton exchange membrane fuel cells (PEMFCs).[1]. The structures were solved by the direct methods,[37] which revealed the position of all non-hydrogen atoms For both the anode and cathode, the catalyst layer ink consisted of Pt/C (40% Pt on Vulcan XC-72, E-TEK) with a Pt load of 1 mg Pt·cm−2, 30% Nafion (1100 EW), and 2:1 isopropanol/water mixture as the dispersion medium. The supplied current density was recorded during the extent of the experiment
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
