title: Three Series of Sulfo-Functionalized Mixed-Linker CAU-10 Analogues: Sorption Properties, Proton Conductivity, and Catalytic Activity.
abstract: Ten mixed-linker metal-organic frameworks [Al(OH)(m-BDC-X)(1-y)(m-BDC-SO3H)y] (H2BDC = 1,3-benzenedicarboxylic acid; X = H, NO2, OH) exhibiting the CAU-10-type structure were synthesized. The compounds can be grouped into three series according to the combination of ligands employed. The three series of compounds were obtained by employing different ratios of m-H2 BDC-X and m-H2BDC-SO3Li. The resulting compounds, which are denoted CAU-10-H/Sx, -N/Sx and -O/Sx, show exceptionally high thermal stability for sulfonated materials of up to 350 °C. Detailed characterization with special focus on polarity and acidity was performed, and the impact of the additional SO3H groups is clearly demonstrated by changes in the sorption affinities/capacities towards several gases and water vapor. In addition, selected samples were evaluated for proton conductivity and as catalysts for the gas-phase dehydration of ethanol to ethylene. While only very low proton conductivities were observed, a pronounced increase in catalytic activity was achieved. Although reactions were performed at temperatures of 250 and 300 °C for more than 40 h, no desulfonation and no loss of crystallinity were observed, and stable ethanol conversion resulted. This demonstrates the high stability of this material.
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118 Kiel (Germany).
authors.forename: Nele
authors.initials: N
authors.lastname: Reimer
authors.affiliation: Centre for Surface Chemistry and Catalysis, University of Leuven, Kasteelpark Arenberg 23, 3001 Leuven (Belgium).
authors.forename: Bart
authors.initials: B
authors.lastname: Bueken
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118 Kiel (Germany).
authors.forename: Sebastian
authors.initials: S
authors.lastname: Leubner
authors.affiliation: Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg (Germany).
authors.forename: Christopher
authors.initials: C
authors.lastname: Seidler
authors.affiliation: Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg (Germany).
authors.forename: Michael
authors.initials: M
authors.lastname: Wark
authors.affiliation: Centre for Surface Chemistry and Catalysis, University of Leuven, Kasteelpark Arenberg 23, 3001 Leuven (Belgium).
authors.forename: Dirk
authors.initials: D
authors.lastname: De Vos
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118 Kiel (Germany). stock@ac.uni-kiel.de.
authors.forename: Norbert
authors.initials: N
authors.lastname: Stock
keywords: aluminum; conducting materials; heterogeneous catalysis; metal-organic frameworks; microporous materials