Smart paper transformer for enhanced catalytic efficiency and reusability of nanocatalysts

Patent metadata

Field	Value
Publication number	US-11420188-B2
Application number	US-201916687039-A
Country	US
Kind code	B2
Filing date	Nov 18, 2019
Priority date	Nov 16, 2018
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A method of synthesizing a smart paper transformer is provided. The method comprises combining paper with HAuCl4 and stirring together in an aqueous solution to form a pulp. The pulp is treated with NaBH4 aqueous solution. The treated pulp is then washed and centrifuged with water a number of times to form a gold nanosponge (AuNS) catalyst pulp.

First claim

The invention claimed is:

1. A method of catalytic reduction on a paper transformer, the method comprising:
stirring a gold nanosponge (AuNS) catalyst in a solid paper phase into water to form an AuNS catalyst pulp;
adding an aqueous solution of a nitroaromatic compound and NaBH 4 to the AuNS catalyst pulp and stirring, thereby reducing the nitroaromatic compound; and
regenerating used AuNS catalyst.

2. The method of claim 1 , further comprising:
washing and centrifuging the AuNS catalyst pulp with water a number of times after the the catalytic reduction of the nitroaromatic compound; and
drying the AuNS catalyst pulp to transform the AuNS catalyst back to a solid paper phase to recover the AuNS catalyst.

3. The method of claim 2 , wherein the AuNS catalyst pulp maintains a catalytic efficiency of over 90% for up to 15 use cycles.

4. The method of claim 1 , wherein a molar ratio of the NaBH 4 to the nitroaromatic compound is 100 or less.

5. The method of claim 1 , wherein the nitroaromatic compound is p-nitrophenol.

6. The method of claim 1 , wherein the nitroaromatic compound is o-nitroaniline.

7. The method of claim 1 , wherein the regenerating of the used AuNS catalyst comprises:
combining waste catalyst with HAuCl 4 and stirring together in an aqueous solution to form a pulp;
adding NaBH 4 to the pulp and stirring to reduce Au 3+ ;
centrifuging and washing the pulp; and
drying the pulp.

8. The method of claim 7 , wherein the NaBH 4 and the pulp are stirred for one hour.

9. The method of claim 7 , wherein the pulp is centrifuged and washed three times.

10. The method of claim 7 , wherein the pulp is dried at 60° C. for six hours.

11. The method of claim 1 , wherein the AuNS catalyst pulp has a k value of 0.0106s −1 .

12. The method of claim 1 , wherein transformation of the solid paper phase to the pulp phase enables uniform distribution of the AuNS catalyst in a solution.

13. The method of claim 1 , wherein the regenerating of the used AuNS catalyst comprises:
combining used AuNS catalyst pulp with HAuCl 4 .3H 2 O and stirring together in an aqueous solution to form a pulp;
treating the pulp with NaBH 4 aqueous solution;
washing and centrifuging the treated pulp with water a number of times; and
drying the treated pulp.

14. The method of claim 1 , wherein the used AuNS catalyst are regenerated after 16 use cycles.

Assignees

• Univ Texas

Inventors

• Li Xiujun
• Jin Qijie

Classifications

• B01J2235/10

  Infrared [IR] · 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

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• 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