Photocatalyst, method for preparing the same, and production of hydrogen using the same

• US 5,865,960 A
• Filed: 02/24/1997
• Issued: 02/02/1999
• Est. Priority Date: 08/30/1994
• Status: Expired due to Fees

• Current Assignee: Korea Research Institute of Chemical Technology
• Original Assignee: Korea Research Institute of Chemical Technology
• Inventors: Park, Dae Chul, Chang, Duck Rye, Chung, Kyeong Hwan
• Primary Examiner(s): Gorgos, Kathryn
• Assistant Examiner(s): WONG, EDNA
• Application Number:
  US08/793,354
• Time in Patent Office: 708 Days
• Field of Search: 204/157.52, 502/344, 502/353
• US Class Current: 204/157.52
• CPC Class Codes: B01J 23/20 Vanadium, niobium or tantalum
• CPC Class Codes: C01B 13/0207 Water
• CPC Class Codes: C01B 3/065 from a hydride
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

A photocatalyst for the preparation of hydrogen consisting of a catalytically active ingredient, cesium (Cs), impregnated in a support, K₄ Nb₆ O₁₇, represented by Formula I as follows:

Cs (a) /K.sub.4 Nb.sub.6 O.sub.17

wherein a is an amount of the catalytically active ingredient impregnated in the support and has a value of between 0.05 to 5.0% by weight based on total weight of the support. Such a catalyst is prepared by combining K₂ CO₃ with Nb₂ O₅ in a mole ratio of 2:3; sintering the combination at a temperature of about 1,200°-1,300° C. to produce the support, K₄ Nb₆ O₁₇ ; and impregnating the support with the catalytically active ingredient, Cs. Hydrogen is efficiently produced by illuminating an ultraviolet light on an aqueous solution added with an oxygen-containing organic promoter at a reaction temperature of about 15°-80° C., under a reaction pressure of about 0.1-3.0 atm, in the presence of the photocatalyst.

Claims

1. A method for preparing a photocatalyst represented by Formula I as follows:

space="preserve" listing-type="equation">Cs(a)/K.sub.4 Nb.sub.6 O.sub.17

wherein a is an amount of catalytically active ingredient, Cs, impregnated in the support K₄ Nb₆ O₁₇, comprising the steps of;

combining K₂ CO₃ with Nb₂ O₅ in a mole ratio of 2;

3;

sintering the combination at a temperature of about 1,200°

-1,300°

C. to produce the support, K₄ Nb₆ O₁₇ ; and

impregnating the support with the catalytically active ingredient, Cs.

2. The method of claim 1, wherein the impregnating step is accomplished by mixing the support in a Cs₂ CO₃ aqueous solution, stirring the mixture overnight at room temperature, distilling the mixture in vacuo to obtain a dried mixture and sintering the dried mixture at a temperature of about 100°

-300°

C., for a period of about 1-5 hours.

3. A method for producing hydrogen, comprising the steps of:

illuminating an ultraviolet light on an aqueous solution comprising an oxygen-containing organic promoter, at a reaction temperature of about 15°

-80°

C., under a reaction pressure of about 0.1-3.0 atm, in contact with a photocatalyst according to claim 1; and

generating hydrogen;

wherein the oxygen-containing organic promoter is a compound containing an aldehyde group.

4. The method of claim 3, wherein the reaction pressure is atmospheric pressure.

5. The method of claim 3, wherein the oxygen-containing organic promoter is a compound containing an alcohol group.

6. The method of claim 3, wherein the oxygen-containing organic promoter is added in an amount of about 5-30% by volume based on total volume of the aqueous solution.

7. The method of claim 1, wherein a has a value of between 0.05 to 5.0% by weight, based on the total weight of the support.

8. The method of claim 1, wherein the catalytically active ingredient is impregnated in an amount between 0.1-3.0 wt %.