Method of preparing catalyst having Pt—Pd dispersed polymer electrolyte multilayers treated with sulfuric acid
View Patent ↗Disclosed herein is a method of preparing a catalyst having Pt—Pd dispersed in polymer electrolyte multilayers, suitable for use in production of hydrogen peroxide, wherein the use of the catalyst prepared by forming polymer electrolyte multilayers on an anionic resin support and performing sulfuric acid treatment and loading (insertion or attachment) of Pt—Pd particles can result in high hydrogen conversion, hydrogen selectivity and hydrogen peroxide yield for a long period of time.
1. A method of preparing a catalyst having polymer electrolyte multilayers, comprising:
a) sequentially forming a cationic polymer electrolyte layer and an anionic polymer electrolyte layer on an anionic support to form polymer electrolyte multilayers;
b) treating the polymer electrolyte multilayers of step a) with sulfuric acid; and
c) loading or inserting a Pt precursor and a Pd precursor into the polymer electrolyte multilayers treated with sulfuric acid in step b), and reducing the Pt precursor and the Pd precursor by a reductant to form Pt—Pd metal particles dispersed in the polymer electrolyte multilayers,
wherein a Pt/Pd atomic ratio in the reduced Pt—Pd metal particles is 0.02 to 0.15.
2. The method of claim 1 , wherein the anionic support has a sulfonic acid functional group.
3. The method of claim 1 , wherein step a) is repeated two or more times.
4. The method of claim 1 , wherein step a) is performed by bringing a cationic polymer electrolyte solution and an anionic polymer electrolyte solution into sequential contact with the anionic support.
5. The method of claim 1 , wherein the cationic polymer electrolyte is poly(allylamine)hydrochloride, polydiallyldimethylammonium, poly(ethyleneimine), poly(acrylamide-co-diallyldimethylammonium) or a combination thereof.
6. The method of claim 1 , wherein the anionic polymer electrolyte is poly(4-styrenesulfonate), poly(acrylic acid), poly(acrylamide), poly(vinylphosphonic acid), poly(2-acrylamido-2-methyl-11-propanesulfonic acid), poly(anetholesulfonic acid), poly(vinylsulfonate) or a combination thereof.
7. The method of claim 4 , wherein a solvent for the cationic polymer electrolyte solution and the anionic polymer electrolyte solution is water, n-hexane, ethanol, triethylamine, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), ethylacetate, isopropylalcohol, acetone, acetonitrile, benzene, butylalcohol, chloroform, diethylether, or a mixture thereof.
8. The method of claim 1 , wherein the sulfuric acid used in step b) is an aqueous sulfuric acid solution with a concentration of 0.05 to 8 M.
9. The method of claim 8 , wherein step b) is performed by bringing the aqueous sulfuric acid solution into contact with the polymer electrolyte multilayers at 20 to 120° C. for 5 to 600 min.
10. The method of claim 1 , wherein step c) comprises bringing a solution containing the Pt precursor and the Pd precursor into contact with the support having the polymer electrolyte multilayers,
wherein the Pt precursor and the Pd precursor in the solution have a concentration of 0.05 to 10 mM.
11. The method of claim 10 , wherein the solution containing the Pt precursor and the Pd precursor has a pH of 1 to 6.
12. The method of claim 1 , wherein an amount of the reduced Pt—Pd metal particles in the catalyst is 0.01 to 5 wt %.
13. The method of claim 1 , wherein the Pt/Pd atomic ratio in the reduced Pt—Pd metal particles is 0.05 to 0.1.
14. The method of claim 1 , wherein the reduced Pt—Pd metal particles have a size of 1 to 100 nm.
15. A method of producing hydrogen peroxide, comprising:
1) preparing a catalyst having polymer electrolyte multilayers, wherein said preparing comprises:
a) sequentially forming a cationic polymer electrolyte layer and an anionic polymer electrolyte layer on an anionic support to form polymer electrolyte multilayers;
b) treating the polymer electrolyte multilayers of step a) with sulfuric acid; and
c) loading or inserting a Pt precursor and a Pd precursor into the polymer electrolyte multilayers treated with sulfuric acid in step b), and reducing the Pt precursor and the Pd precursor by a reductant to form Pt-Pd metal particles dispersed in the polymer electrolyte multilayers,
wherein a Pt/Pd atomic ratio in the reduced Pt-Pd metal particles is 0.02 to 0.15;
2 ) reacting hydrogen and oxygen using the catalyst having polymer electrolyte multilayers.
16. The method of claim 15 , wherein the reaction is performed in a liquid-phase reaction using a solvent containing 100 ppm or less of a halogen additive and free of an acid promoter.
17. The method of claim 15 , wherein the reaction is performed at a reaction temperature of 20 to 60° C. and at a reaction pressure of 35 to 70 bar.