TY - CONF A1 - Kjaervik, Marit A1 - Dietrich, P. A1 - Thissen, A. A1 - Defedov, A. A1 - Natzeck, C. A1 - Wöll, C. A1 - Unger, Wolfgang T1 - Investigations of HKUST-1 exposed to argon, pyridine, methanol and water vapor by near-ambient pressure XPS N2 - Metal-organic frameworks (MOFs) are suitable materials for gas storage of small molecules due to their nanoporous, crystalline structure. The extensively studied MOF HKUST-1 consist of Cu(II)-dimers in a paddlewheel structure, with 1,3,5-benzenetricarboxylic acid (BTC) as organic linker. Instability to humidity remains an issue for many types of MOFs, and for HKUST-1, it has been found that exposure to water vapor creates a surface barrier which reduces the gas uptake rate. Near-ambient pressure XPS (NAP-XPS) is a promising method for investigations of the stability and interaction of HKUST-1 with various gas molecules. The oxidation state of copper can be monitored before, during and after exposure to various gases. This does not only provide information on the stability of the MOFs, but also on the interaction with the gas molecules and the reversibility of the processes. NAP-XPS measurements of HKUST-1 exposed to methanol, pyridine and water vapor were performed with EnviroESCA, a laboratory NAP-XPS instrument developed by SPECS. Cu 2p, O 1s and C 1s core level spectra were acquired in pressure ranging from 10-5 to 8 mbar to assess the oxidation state of copper and the stability of the organic linker. HKUST-1 does not show interaction with pyridine, but there are indications of copper-reduction upon exposure to methanol and water vapor. Radiation induced damage is considered and two different approaches for determining the ratio of Cu(I) to Cu(II) will be discussed. T2 - Bunsentagung 2019 - 118th General Assembly of the German Bunsen Society for Physical Chemistry CY - Jena, Germany DA - 30.05.2019 KW - XPS KW - MOF KW - HKUST-1 KW - NAP-XPS KW - Metal organic frameworks PY - 2019 AN - OPUS4-48195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -