Method for producing hydrophobized mixed metal oxide nanoparticles and use thereof for heterogeneous catalysis

Patent metadata

Field	Value
Publication number	US-10874891-B2
Application number	US-201615737299-A
Country	US
Kind code	B2
Filing date	Jul 1, 2016
Priority date	Jul 2, 2015
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

The invention relates to methods for producing hydrophobized, doped or non-doped mixed metal oxide nanoparticles or doped metal oxide nanoparticles by flame spray pyrolysis, wherein a combustible precursor solution A, containing at least two metal alkyloates of general formula Me(OOC—R) x with differing metals Me, or a combustible precursor solution B containing at least one metal alkyloate of general formula Me(OOC—R) x and at least one metal salt containing a metal ion Me and at least one metal salt containing a metal ion Me, with Me selected from metal ions of the subgroups of the periodic system of the elements, with R=alkyl or aryl, wherein the alkyl chain is branched or straight, and wherein x corresponds to the oxidation step of the metal ion, is used in stoichiometric excess relative to a quantity of oxygen, and wherein a combustion ratio Φ of 3.5 bis 0.4 is established, and hydrophobized nanoparticles and the use thereof.

First claim

The invention claimed is:

1. A method for producing hydrophobized, hopcalite nanoparticles on or in which carbon is deposited, with variable carbon content by flame spray pyrolysis, wherein a combustible precursor solution A, containing at least two metal alkyloates of which include at least one manganese alkyloate and at least one copper alkyloate, or a combustible precursor solution B, containing a metal alkyloate/metal salt mixture, selected from copper alkyloate and manganese alkyloate,
said metal salt containing a metal ion Me, with Me selected from metal ions of the subgroups of the periodic system of the elements,
wherein in precursor solution B, Me (metal alkyloate)≠Me (metal salt), and
wherein the alkyl chain in the alkyloates of precursor solution A and precursor solution B is used in stoichiometric excess based on a quantity of oxygen in a dispersion gas, and wherein a combustion ratio of Φ from 3.5 bis 0.4 is established.

2. The method according to claim 1 , characterized in that each precursor solution contains at least one organic solvent selected from n-hexane, ethanol, 2-ethylhexanoic acid, methanol, acetic acid, n-heptane, xylene, toluene, benzene, trichloromethane, ethylbenzene and mixtures of these.

3. The method according to claim 1 , characterized in that a quartz tube is placed over the combustion flame.

4. The method according to claim 1 , characterized in that the precursor solution A contains the two metal alkyloates with a molar ratio of 10:90 to 90:10.

5. The method according to claim 1 , characterized in that in precursor solution B the molar ratio of the total quantity of the metal alkyloates to the total quantity of metal salt is 80:20 to 99:1.

6. Hydrophobized hopcalite nanoparticles, containing carbon at a content of 0.1 to 5 wt.-%, based on the total quantity of nanoparticles, and a hydrophobicity index of 0.2 to 1.

7. Hydrophobized hopcalite nanoparticles according to claim 6 , characterized in that the nanoparticles have a specific surface of 10 to 250 m 2 /g.

8. A method of oxidation of carbon monoxide and/or formaldehyde, said method comprising: providing the hydrophobized hopcalite nanoparticles according to claim 7 and using said hydrophobized hopcalite nanoparticles for the oxidation of carbon monoxide and/or formaldehyde.

9. A method of oxidation of carbon monoxide and/or formaldehyde, said method comprising: providing the hydrophobized hopcalite nanoparticles according to claim 7 in respirator masks.

Assignees

• Univ Dresden Tech

Inventors

• Biemelt Tim
• Grothe Julia
• Kaskel Stefan
• Wegner Karl

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/45

  Nanoparticles · CPC title

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title