Three Series of Sulfo‐Functionalized Mixed‐Linker CAU‐10 Analogues: Sorption Properties, Proton Conductivity, and Catalytic Activity. Issue 35 (17th July 2015)

• Record Type: Journal Article
• Authors: Reimer, Nele; Bueken, Bart; Leubner, Sebastian; Seidler, Christopher; Wark, Michael; De Vos, Dirk; Stock, Norbert
• Is Part Of: Chemistry. Volume 21:Issue 35(2015)
• Page Start: 12517
• Page End: 12524
• Publication Date: 2015-07-17
• Subjects: aluminum -- conducting materials -- heterogeneous catalysis -- metal–organic frameworks -- microporous materials; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201501502
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Ten mixed‐linker metal–organic frameworks [Al(OH)( m ‐BDC‐X)1− y ( m ‐BDC‐SO3 H) y ] (H2 BDC=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 ‐H2 BDC‐SO3 Li. The resulting compounds, which are denoted CAU‐10‐H/S x, ‐N/S x and ‐O/S x, 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 SO3 H 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. Abstract : Mix it up! Introduction of sulfo groups into CAU‐10‐H, ‐NO2, and ‐OH metal–organic frameworks by mixed‐linker synthesis strongly influences the acidity and polarity of the resulting materials. Besides the impact on the sorption behavior, high catalytic activity is observed in the gas‐phase dehydration of ethanol to ethylene at a reaction temperature of 300 °C (see figure).