title: Unravelling the Proton Conduction Mechanism from Room Temperature to 553 K in a 3D Inorganic Coordination Framework.
abstract: The preparation of proton-conducting materials that are functional and stable at intermediate temperatures (393-573 K) is a focal point of fuel cell development. The purely inorganic material, HNd(IO3)4, which possesses a dense 3D framework structure, can reach a maximum of 4.6 × 10(-4) S·cm(-1) at 353 K and 95% relative humidity and exhibit a high conductivity of 8.0 × 10(-5) S·cm(-1) from 373 to 553 K under the flow of wet N2. HNd(IO3)4 exhibits a variety of improvements including high thermal stability, low solubility in water, and resistance to reducing atmosphere. The proton conductivity in such a wide temperature range originates from the intrinsic liberated protons in the structure and the resulting 1D hydrogen-bonding network confirmed by bond valence sum calculation and solid-state NMR analysis. Moreover, two different activation energies are observed in different temperature regions (0.23 eV below 373 K and 0.026 eV from 373 to 553 K), indicating that two types of proton motion are responsible for proton diffusion, as further domenstrated by temperature-dependent open-circuit voltage hysteresis in a tested fuel cell assembly as well as variable-temperature and double quantum filtered solid-state NMR measurements.
authors.forename: Yaxing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology , Yancheng 224001, Jiangsu China.
authors.forename: Zetian
authors.initials: Z
authors.lastname: Tao
authors.forename: Xuemiao
authors.initials: X
authors.lastname: Yin
authors.forename: Jie
authors.initials: J
authors.lastname: Shu
authors.forename: Lanhua
authors.initials: L
authors.lastname: Chen
authors.forename: Daopeng
authors.initials: D
authors.lastname: Sheng
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Chai
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University , 95 Chieftain Way, Tallahassee, Florida 32306, United States.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Albrecht-Schmitt
authors.forename: Shuao
authors.initials: S
authors.lastname: Wang
mesh_terms: D007452:Iodates / Q000737:chemistry*; D009354:Neodymium / Q000737:chemistry*; D011522:Protons; D013696:Temperature
chemical_list: D007452:Iodates; D011522:Protons; D009354:Neodymium