Bayer Aktiengesellschaft

Horst Koller

Wolfgang Biedermann

Karlfried Wedemeyer

Hans-Helmut Schwarz

Eberhard Zirngiebl

Oskar Weissel

Ursula Pentling

Joerg-Dietrich Jentsch

Volker Glock

Bernd Pennemann

New hydrated niobium oxide and hydrated tantalum oxide catalysts containing pores having diameters in the range from 0.4 to 10,000 nm are characterized in that the volume of the pores of the catalyst having a diameter of from 100 to 1000 nm is at least 30% of the total pore volume of the catalyst. The catalysts can be prepared by mixing hydrated niobium oxide or hydrated tantalum oxide with an inert solid and converting this mixture into a solid pellet form, with the pressure in the apparatus for preparing catalysts in pellet form being set in such a way that the volume of the pores of the catalyst having a diameter of from 100 to 1000 nm is at least 30% of the total pore volume of the catalyst. Such catalysts are particularly suitable for preparing N-alkylanilines from anilines and alkanols.

Hydrated niobium oxide and hydrated tantalum oxide catalysts, their

Thymol can be prepared on a continuous basis by reacting m-cresol with propylene and/or compounds which eliminate propylene, over aluminum oxide catalysts in the presence of a nitrogen base. The aluminum oxide catalyst is an active or activated hydrated aluminum oxide having a particle size between 0.5 and 20 mm, a BET surface area of at least 200 m.sup.2 /g, a porosity equal to or greater than 0.5 mm/g, a boehmite content of 5 to 40 percent by weight, and an X-ray spectrum which shows the reflections of .gamma.-alumina wherein the content of microcrystalline constituents is less than 50 percent by weight.

Process for preparing thymol

A hydrogenation catalyst containing cobalt, manganese and copper in the form of their oxides and alkali metal oxide and silicon dioxide. A weight ratio of cobalt to maganese is 25:1 to 1:1, and the copper content is 0.01 to 2% by weight based on a total weight of the catalyst. The catalyst is prepared by adding an excess of an aqueous solution of a hydroxide, bicarbonate or carbonate of an alkali metal to an aqueous solution of water-soluble cobalt salts, manganese-(II) salts and copper salts to form a precipitate. Thereafter an aqueous solution of an alkali metal silicate or SiO.sub.2 sol is added to the precipitate which is filtered off and washed with water to remove excess alkali metal hydroxide, bicarbonate or carbonate. The precipitate is then dried and calcined to form the catalyst.

Hydrogenation catalyst and process for preparing same

Hydroxydiphenyl is prepared by dehydrogenating a starting material comprising completely and/or partly hydrogenated hydroxydiphenyl in a gaseous phase in the presence of a dehydrogenation catalyst and a compound having the formula ##SPC1## Wherein

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Krefeld, Germany

Horst Koller