Iron oxide supported rhodium catalyst for nitroarene reduction

Patent metadata

Field	Value
Publication number	US-11452992-B2
Application number	US-201916359409-A
Country	US
Kind code	B2
Filing date	Mar 20, 2019
Priority date	Mar 20, 2019
Publication date	Sep 27, 2022
Grant date	Sep 27, 2022

Abstract

A supported catalyst having rhodium particles with an average diameter of less than 1 nm disposed on a support material containing magnetic iron oxide (e.g. Fe3O4). A method of producing the supported catalyst and a process of reducing nitroarenes to corresponding aromatic amines employing the supported catalyst with a high product yield are also described. The supported catalyst may be recovered with ease using an external magnet and reused.

First claim

The invention claimed is:

1. A supported catalyst, comprising:
a support material comprising Fe 3 O 4 ; and
a catalytic material comprising rhodium disposed on the support material;
wherein:
the catalytic material is in the form of subnanoparticles having an average particle size of 0.2-0.99 nm;
the rhodium is present in an amount of 1-20 wt % relative to a total weight of the supported catalyst; and
the support material is devoid of Al 2 O 3 .

2. The supported catalyst of claim 1 , wherein the Fe 3 O 4 is in the form of nanospheres.

3. The supported catalyst of claim 2 , wherein the nanospheres have an average particle size of 5-25 nm.

4. The supported catalyst of claim 1 , wherein the rhodium is present in an amount of 4-10 wt % relative to a total weight of the supported catalyst.

5. The supported catalyst of claim 1 , which has a BET surface area in a range of 100-180 m 2 /g.

6. The supported catalyst of claim 1 , which has a saturation magnetization value in a range of 50-75 emu/g.

7. The supported catalyst of claim 1 , wherein the support material consists of Fe 3 O 4 .

8. A method of preparing the supported catalyst of claim 1 , the method comprising:
mixing the support material comprising Fe 3 O 4 which is devoid of Al 2 O 3 with a solution comprising a rhodium salt to form a suspension;
heating the suspension to form a reaction mixture; and
mixing ammonium hydroxide with the reaction mixture thereby forming the supported catalyst.

9. The method of claim 8 , wherein the rhodium salt is rhodium(III) nitrate.

10. The method of claim 8 , wherein the heating is carried out at a temperature of 50-120° C.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Shaikh M Nasiruzzaman
• Aziz Md Abdul

Classifications

• B01J35/70

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

• B01J35/45

  Nanoparticles · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/393

  Metal or metal oxide crystallite size · CPC title

• B01J2235/00

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