Back to results
US 2026/0125802 A1Published application
Water electrolysis using iron-doped zif-8 catalysts
AssigneeKing Fahd University of Petroleum and Minerals
InventorsMunzir Hamedelniel Mohamed SULIMAN, Muhammad USMAN, Aasif HELAL
Life of this patent
Estimating the term…
Abstract
A method of oxygen evolution comprising contacting a working electrode including an iron-doped zeolitic imidazolate framework-8 (Fe-ZIF-8), a counter electrode, and a reference electrode with an aqueous electrolytic solution, applying a potential, and forming oxygen at the working electrode. The iron-doped ZIF-8 includes iron in an amount of 5 to 55 weight percent relative to the combined weight of iron and zinc in the iron-doped ZIF-8. The Fe-ZIF-8 structures are nanoparticles with a longest dimension of 0.5 to 5 μm. The working electrode has an overpotential of 180 to 190 mV vs RHE at a current density of 10 mA/cm2.
Claims20
1:
- A method of oxygen evolution, comprising:
- contacting a working electrode comprising an iron-doped zeolitic imidazolate framework-8, a counter electrode, and a reference electrode with an aqueous electrolytic solution,
- wherein the iron-doped zeolitic imidazolate framework-8 comprises iron in an amount of 5 to 55 percent by weight based on the total weight of iron and zinc in the iron-doped zeolitic imidazolate framework-8,
- wherein the iron-doped zeolitic imidazolate framework-8 is in the form of nanoparticles with a longest dimension of 0.5 to 5 μm,
- applying a potential;
- and
- forming oxygen at the working electrode,
- wherein the working electrode has an overpotential of 180 to 190 mV vs RHE at a current density of 10 mA/cm2.
5 more elements
2:
- The method of claim 1, further comprising:
- forming the iron-doped zeolitic imidazolate framework-8 by:
- dissolving 2-methylimidazole in a polar solvent to form a first solution;
- dissolving a zinc salt and an iron salt in a polar solvent to form a second solution;
- mixing the first solution and the second solution to form a precipitate;
- collecting and washing the precipitate;
- and
- drying the precipitate at a temperature of 50 to 70° C. for 8 to 24 hours to form the iron-doped zeolitic imidazolate framework-8.
5 more elements
3:
- The method of claim 1, wherein the working electrode is a nickel foam substrate coated with a mixture comprising the iron-doped zeolitic imidazolate framework-8 and a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer.
4:
- The method of claim 3, further comprising:
- forming the working electrode by:
- dispersing the iron-doped zeolitic imidazolate framework-8, the sulfonated tetrafluoroethylene-based fluoropolymer-copolymer, and a polar solvent in water to form a mixture;
- sonicating the mixture for 10 to 30 minutes;
- and
- coating the mixture onto the nickel foam substrate.
3 more elements
5:
- The method of claim 4, wherein 50 to 150 μL of the mixture is coated onto the nickel foam substrate.
6:
- The method of claim 4, wherein the coating includes spray coating the mixture onto the nickel foam substrate.
7:
- The method of claim 1, wherein the iron-doped zeolitic imidazolate framework-8 comprises iron in an amount of 5 to 15 percent by weight based on the total weight of iron and zinc in the iron-doped zeolitic imidazolate framework-8 and the iron-doped zeolitic imidazolate framework-8 is in the form of nanoparticles with a longest dimension of 0.1 to 1 μm.
8:
- The method of claim 1, wherein the working electrode has an overpotential of 260 to 280 mV vs RHE at a current density of 55 mA/cm2.
9:
- The method of claim 1, wherein the working electrode has an overpotential of 460 to 480 mV vs RHE at a current density of 150 mA/cm2.
10:
- The method of claim 1, wherein the working electrode is stable for 20 to 28 hours at a current density of 50 mA/cm2.
11:
- The method of claim 1, wherein the working electrode has a double-layer capacitance of 8 to 12 mF/cm2.
12:
- The method of claim 1, wherein the working electrode has a charge transfer resistance of 0.2 to 0.6 Ω/cm2.
13:
- The method of claim 1, wherein a working area of the working electrode is 0.1 to 2 cm2.
14:
- The method of claim 1, wherein the counter electrode is a platinum wire.
15:
- The method of claim 1, wherein the reference electrode is a mercury/mercury oxide (Hg/HgO) electrode.
16:
- The method of claim 1, wherein the aqueous electrolytic solution comprises potassium hydroxide.
17:
- The method of claim 1, wherein the iron-doped zeolitic imidazolate framework-8 comprises iron in an amount of 5 to 15 percent by weight based on the total weight of iron and zinc in the iron-doped zeolitic imidazolate framework-8.
18:
- The method of claim 1, further comprising:
- producing hydrogen at the working electrode.
19:
- The method of claim 1, further comprising:
- producing formate at the working electrode.
20:
- The method of claim 1, further comprising:
- producing a hydrogenated product at the working electrode.