Nanocrystalline copper oxide, and method for the production thereof

Abstract

A nanocrystalline supported or unsupported copper oxide with a residual carbon content of <10% and a BET surface area >95 m 2 /g. Further, a method for the production of a supported or unsupported nanocrystalline copper oxide as well as the use thereof in catalysis, in particular in the steam reforming of methanol or in the hydrogenation of esters.

1 . Nanocrystalline copper oxide with a BET surface area >95 m 2 /g. 
     
     
         2 . Nanocrystalline copper oxide according to  claim 1 , wherein the BET surface area lies in a range of from 95 to 300 m 2 /g. 
     
     
         3 . Nanocrystalline copper oxide according to  claim 2  with a carbon content of <5%. 
     
     
         4 . Nanocrystalline copper oxide according to  claim 3  with a particle size of <100 μm. 
     
     
         5 . Supported nanocrystalline copper oxide according to  claim 1 , wherein the support contains a material selected from the group consisting of SiO 2 , ZrO 2 , bentonite, montmorillonite, Al 2 O 3 , TiO 2 , ZnO, MgSiO 4 , aluminosilicates, or mixtures thereof. 
     
     
         6 . Supported nanocrystalline copper oxide according to  claim 5  with a particle size in the range of from 50 nm to 200 μm. 
     
     
         7 . Shaped bodies containing copper oxide and/or supported copper oxide according to  claim 1 . 
     
     
         8 . Method for the production of nanocrystalline copper oxide comprising the steps of
 a) the introduction of a copper starting compound into a reaction chamber by means of a carrier fluid, and wherein the copper starting compound is introduced into the reaction chamber in the form of a solution, slurry, suspension or in solid aggregate state,   b) a thermal treatment of the copper starting compound in a treatment zone of the reaction chamber by means of a pulsating flow at a temperature of from 200 to 500° C.,   c) the formation of nanocrystalline copper oxide material,   d) the discharge of the nanocrystalline copper oxide material obtained in steps b) and c) from the reactor.   
     
     
         9 . Method according to  claim 8 , wherein the copper starting compound is used as suspension with an average particle size of <10 μm. 
     
     
         10 . Method according to  claim 8 , wherein the particle size is obtained by grinding the copper starting compound before the production of the suspension. 
     
     
         11 . Method according to  claim 8 , wherein the copper starting compound is used as solution. 
     
     
         12 . Method according to  claim 8 , wherein, as copper starting compound, a compound selected from the group consisting of a copper salt of an organic acid, a hydroxide, a nitrate, a carbonate, a hydroxocarbonate or mixtures thereof is used. 
     
     
         13 . Method according to  claim 12 , wherein, as organic acid, an organic acid with fewer than 9 carbon atoms is used. 
     
     
         14 . Method according to  claim 13 , wherein the organic acid is selected from the group consisting of glyoxalic acid, oxalic acid, citric acid, derivatives thereof as well as carbonic acid (carbonate). 
     
     
         15 . Method according to  claim 7 , wherein, in addition to the copper starting compound, further compounds are also used. 
     
     
         16 . Method according to  claim 15 , wherein the further compounds are selected from the group consisting of compounds of silicon, tin, magnesium, titanium, aluminium, zirconium, zinc as well as mixtures thereof. 
     
     
         17 . Use of a nanocrystalline supported or unsupported copper oxide according to  claim 1  as catalyst or catalyst precursor. 
     
     
         18 . Use according to  claim 17  for the steam reforming of methanol or for the hydrogenation of esters. 
     
     
         19 . Use according to  claim 17 , wherein the supported or unsupported copper oxide is reduced to metallic copper before use in a catalytic reaction. 
     
     
         20 . Copper-containing catalyst that can be obtained by reduction of the nanocrystalline supported or unsupported copper oxide according to  claim 1 .