A high-temperature proton exchange membrane was fabricated based on polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) blend polymer nanofibers. Using electrospinning method, abundant small ionic clusters can be formed and agglomerated on membrane surface, which would facilitate the proton conductivity. To further enhance the conductivity, phosphoric acid (PA) retention as well as mechanical strength, sulfamic acid (SA)-doped metal-organic framework MIL-101 was incorporated into PVP-PVDF blend nanofiber membranes. As a result, the anhydrous proton conductivity of the composite SA/MIL101@PVP-PVDF membrane reached 0.237 S cm at 160 °C at a moderate acid doping level (ADL) of 12.7. The construction of long-range conducting network by electrospinning method combined with hot-pressing and the synergistic effect between PVP-PVDF, SA/MIL-101 and PA all contribute to the proton conducting behaviors of this composite membrane.
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http://dx.doi.org/10.1039/d1ra04307b | DOI Listing |
Dalton Trans
January 2025
Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan, Rayong 21210, Thailand.
Dinuclear aluminum complexes bearing a constrained 'indanimine' ligand based on a short hydrazine bridge were synthesized. Single-crystal X-ray crystallography reveals bimetallic penta-coordinated aluminum centers having a distorted trigonal bipyramidal geometry. A short Al-Al distance of 4.
View Article and Find Full Text PDFNat Commun
January 2025
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, PR China.
Transition-metal layered double hydroxides are widely utilized as electrocatalysts for the oxygen evolution reaction (OER), undergoing dynamic transformation into active oxyhydroxides during electrochemical operation. Nonetheless, our understanding of the non-equilibrium structural changes that occur during this process remains limited. In this study, utilizing in situ energy-dispersive X-ray absorption spectroscopy and machine learning analysis, we reveal the occurrence of deprotonation and elucidate the role of incorporated iron in facilitating the transition from nickel-iron layered double hydroxide (NiFe LDH) into its active oxyhydroxide.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, 414000 Hunan, P. R. China.
The high-temperature proton exchange membranes suffer from weak binding strength for phosphoric acid molecules, which seriously reduce the fuel cell efficiency, especially operation stability. Introduction of microporous material in the membrane can effectively reduce the leaching of phosphoric acid. However, due to the poor compatibility between the polymer and fillers, the membrane's performance significantly reduced at high fillers content.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China.
The fundamental hydrolysis behavior of tetravalent actinide cations (An) with a high charge is crucial for understanding their solution chemistry, particularly in nuclear fuel reprocessing and environmental behavior. Using Th as a reference of the An series, this work employed both the periodic model and the cluster model to calculate the first hydrolysis reaction constant (p) of the Th aqua ion and conducted a detailed evaluation of these approaches. In the periodic model, molecular dynamics (AIMD) simulations of Th in the explicit solvation environment are conducted, using metadynamics and constrained molecular dynamics to calculate p values.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, University of Calgary, 2500 University Dr. NW, T2N 1N4 Calgary, AB Canada.
The extent of coordination-induced bond weakening in aquo and hydroxo ligands bonded to a molybdenum(III) center complexed by a dianionic, pentadentate ligand system was probed by reacting the known complex (BPzPy)Mo(III)-NTf, , with degassed water or dry lithium hydroxide. The aquo adduct was not observed, but two LiNTf-stabilized hydroxo complexes were fully characterized. Computational and experimental work showed that the O-H bond in these complexes was significantly weakened (to ≈57 kcal mol), such that these compounds could be used to form the diamagnetic, neutral terminal molybdenum oxo complex (BPzPy)Mo(IV)O, , by hydrogen atom abstraction using the aryl oxyl reagent ArO• (Ar = 2,4,6-tri--butylphenyl).
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