TY - GEN A1 - Städter, Matthias A1 - Müller, Klaus A1 - Rachow, Fabian A1 - Richter, Matthias A1 - Schmeißer, Dieter T1 - Ambient pressure thermal desorption spectroscopy (AP-TDS) of NiO/SiO2 catalysts T2 - Environmental Earth Sciences N2 - The Sabatier reaction is a key process in the "power-to-gas" application which is considered to con-tribute to future chemical energy storage systems. In this contribution we focus on the catalytic active sites of a NiO catalyst supported on SiO2(NiO/SiO2) which is commonly used in the Sabatier reaction. A novel technique for the characterization of the active sites is presented and dis-cussed using thermal desorption spectroscopy at ambient pressure. This analytical tool is operated under reaction conditions and allows element specific measurements during the catalytic process of CO2 reforming towards methane. Beside the desorption experiments, XPS and XAS measurements of pristine and catalytically used samples are performed to determine the influence of the Sabatier reaction conditions on the surface structure of the catalyst. KW - CO2 KW - NiO KW - TDS KW - XAS KW - XPS Y1 - 2013 U6 - https://doi.org/10.1007/s12665-013-2835-8 SN - 1866-6280 VL - 70 IS - 8 SP - 3779 EP - 3784 ER - TY - GEN A1 - Müller, Klaus A1 - Richter, Matthias A1 - Friedrich, Daniel A1 - Paloumpa, Ioanna A1 - Kramm, Ulrike Ingrid A1 - Schmeißer, Dieter T1 - Spectroscopic characterization of Cobalt–Phthalocyanine electrocatalysts for fuel cell applications T2 - Solid State Ionics N2 - For polymer–electrolyte–membrane fuel cells (PEM-FC), platinumcatalysts on carbon based substrates are state of the art, due to high electrochemical activity and chemical stability in acid electrolytes. High costs of platinum force investigations of alternative catalysts. With respect to the oxygen reduction reaction, possible candidates are transition metal (TM) complexes like TM-porphyrines or TM-phthalocyanines. Pyrolysis on carbon based substrates improves the catalytic activity. Highest activities were found for Fe or Co as transition metal centers. We present results of the pyrolysis of Co-phthalocyanine (CoPc) on carbon black. Besides an investigation of morphology by scanning electron microscopy (SEM) and chemical composition by energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) during pyrolysis, we present a near edge X-ray absorption fine structure (NEXAFS) study of the chemical composition for the related annealing steps. This investigation is accompanied by an electrochemical characterization of the catalytic activity and selectivity. The XPS and NEXAFS data indicate a decomposition of the CoN4(chelate-) complex during pyrolysis. The N1s data for 800 °C show graphite-like, formally pyrrolic and pyridinic like features, without any significant contri-bution of Co. The Co2p data for both, XPS and NEXAFS are dominated by CoO/Co2O3. It can be concluded that during the pyrolysis cobalt particles are formed by the disintegration of CoN4-centers, after pyrolysis these par-ticles become oxidized upon contact with air. KW - Co-phthalocyanine KW - Catalysis KW - Oxygen reduction reaction (ORR) KW - XPS KW - NEXAFS Y1 - 2012 U6 - https://doi.org/10.1016/j.ssi.2011.12.013 SN - 1872-7689 IS - 216 SP - 78 EP - 82 ER - TY - CHAP A1 - Schmeißer, Dieter A1 - Richter, Matthias A1 - Tallarida, Massimo ED - Heber, Jörg ED - Schlom, Darrell ED - Tokura, Yoshinori ED - Waser, Rainer ED - Wuttig, Matthias T1 - Intrinsic defects in TiO2 to explain resistive switching devices T2 - Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany KW - resonant photoelectron spectroscopy KW - Auger processes KW - XPS KW - X-ray absorption spectroscopy Y1 - 2012 SN - 978-3-527-41191-7 U6 - https://doi.org/10.1002/9783527667703.ch45 SP - 255 EP - 256 PB - Wiley-VCH CY - Weinheim ER -