Evonik Degussa Gmbh

Degussa Aktiengesellschaft

Dmc, Inc

Peter Albers

Stipan Katusic

Peter Kress

Harald Herzog

Peter K Kleinschmit

Klaus Deller

Karl Vogel

Conny Vogler

Bertrand Despeyroux

Guido Zimmermann

Carl Voigt

Michael Kraemer

Harald Alff

Emmanuel Auer

Roland Burmeister

Horst Miess

Michael Witzel

Walther Behl

Wolf-Dieter Pfeifer

Peter Kreß

Core-shell particles containing crystalline iron oxide in the core and amorphous silicon dioxide in the shell and in which

Iron-silicon oxide particles having an improved heating rate

Iron-silicon oxide particles with a core and an outer shell have improved heating rates in a magnetic field. The core contains maghemite, magnetite, and haematite. The outer shell is essentially or exclusively silicon dioxide. The crystallite diameter of the haematite determined by X-ray diffraction is greater than 120 nm. A ratio of the brightness of the Debye-Scherrer diffraction ring by electron diffraction at a lattice plane spacing of 0.20+/&#x2212;0.02 nm, comprising maghemite and magnetite, to the brightness of the Debye-Scherrer diffraction ring by electron diffraction at a lattice plane spacing of 0.25+/&#x2212;0.02 nm, comprising maghemite, magnetite and haematite, is no more than 0.2.

Iron-silicon oxide particles having an improved heating rate in an alternating magnetic and electromagnetic field

Pyrogenically prepared zinc oxide powder having a BET surface area of from 10 to 200 m/g, which is in the form of aggregates, the aggregates being composed of particles having different morphologies, and 0-10% of the aggregates being in a circular form, 30-50% being in an ellipsoidal form, 30-50% being in a linear form and 20-30% being in a branched form. It is prepared by reacting a starting mixture containing zinc vapour, a combustible gas and steam or a mixture of steam and carbon dioxide in a flame with an oxygen-containing gas in an oxidation zone, cooling the hot reaction mixture in a quenching zone and separating the solid material from the gas stream, the amount of oxygen in the oxidation zone being greater than the amount necessary for the complete oxidation of the combustible gas and the zinc vapour. The zinc oxide powder can be used as a constituent of sun protection compositions for protection against UV radiation.

Zinc oxide powder aggregates present in circular, ellipsoidal, linear and branched form

Electrocatalyst which are formed of a carbon support, which is a carbon black with an H content of >4000 ppm and, as the catalytically active component, platinum or bi- or multi-metallically doped or alloyed platinum. The electrocatalysts are prepared by deposition of noble metals on the carbon black surface. They can be used for the production of fuel cells.

Electrocatalyst for fuel cells

A process is described for preparing hydrogenation catalysts which contain noble metals, having at least one catalytically active component and optionally promoters and/or modifiers on a support consisting of activated carbon washed with nitric acid. The activated carbon is subjected to an oxidative pretreatment with an oxidizing agent before applying the catalytically active components, promoters and modifiers.

Process for preparing hydrogenation catalysts which contain noble metals

As a result of a special form of the surface coating of Al.sub.2 O.sub.3 catalysts using additional amounts of aluminum ions and very slight amounts of platinum ions, Al.sub.2 O.sub.3 was able to be used as catalyst for continuous operation (150 days and longer) in the preparation of hydrogen cyanide from hydrocarbons and ammonia, preferably in the BMA method.

Method of preparing hydrogen cyanide

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Hanau, Germany

Peter Albers