Organische und anorganische Ionenaustauscher zur heterogen katalysierten Alkylierung von Aromaten

Organic and inorganic ion exchangers as catalysts for the heterogeneous alkylation of aromatics . Ion exchangers has advantages over low molecular for use in industrial alkylation reactions. The reactivity and selectivity behaviour of the polymeric catalysts were found to be markedly influenced by the structure of the polymeric matrix as well as the type and number of the functional groups. In this connection many similarities between inorganic ion exchangers (zeolites) and organic ion exchange resins were detected.     

Untersuchungen zur Haftungsbeeinflussung von Pigmentdrucken durch UV-Laser-Behandlung

Investigations on Adhesion of Pigment Printings by UV-Laser Treatment Investigations on the influence of UV-laser treatment of polyethyleneterephthalate and polyamide fibers and foils on the adhesion properties of pigment printings are presented. It could be shown that even irradiation with low energy densities and low number of pulses applied increases binder film adhesion very efficiently. Some interpretations of the laser action upon adhesion improvement related to surface modification are presented.     

Scale‐up und detaillierte Prozessanalyse eines Membranreaktors am Beispiel einer heterogen katalysierten Veresterung

The combination between reaction and pervaporation has been investigated using the example of a heterogeneous catalysed esterification reaction. The process model parameters have been determined based on experimental investigations and a scale‐up has been performed to the pilot scale. A detailed process analysis leads to optimal operating as well as structural variables and two separation sequences have been suggested.     

Mechanismus der katalysierten Synthese von Kohlenwasserstoffen

On the mechanism of the catalysed synthesis of hydrocarbons . Recent results by independent research teams prove that, in hydrocarbon synthesis over metal catalysts in a reducing atmosphere, the dissociative adsorption of CO is of considerable importance. On the catalyst surface the two fragments, C_ads and O_ads, react swiftly with hydrogen to CH_x,ads and H₂O respectively. CH_x,ads can be either hydrogenated to methane or incorporated in growing chains. This process may be visualized as a cis insertion of a carbene CH_2,ads in a metal-alkyl bond. In the steady state the catalyst surface is predominantly covered with CO_ads, only a small fraction of the surface atoms carrying growing alkyl groups. These have been detected by ¹³C labelling as well as by IR spectroscopy.