Tri-metallic catalyst for ammonia cracking, preparation method therefor, and production method for hydrogen using same

A preparation method of a catalyst for use in ammonia cracking, the method comprising:

• a) preparing an alumina support having a delta-crystal phase by thermally treating spherical boehmite (AlOOH) at a temperature in a range of 750° C. to 900° C.;
• b) supporting a solution in which a yttrium precursor (Y(NO3)3) is mixed and dissolved in a solvent, on the resulting delta-alumina (δ-Al2O3) support by pressurized spray at room temperature, thereby obtaining yttrium/delta-alumina;
• c) drying the yttrium/delta-alumina at a temperature in a range of 100° C. to 120° C. after the supporting, followed by firing at a temperature in a range of 500° C. to 600° C.;
• d) supporting a solution in which a ruthenium precursor (RuCl3) is dissolved in a solvent, on the resulting yttrium/delta-alumina material by pressurized spray at room temperature, thereby obtaining a ruthenium/yttrium/delta-alumina material;
• e) drying the ruthenium/yttrium/delta-alumina material at a temperature in a range of 100° C. to 120° C. after the supporting, followed by firing at a temperature in a range of 500° C. to 600° C., and removing residual Cl through ion exchange;
• f) supporting a solution in which a potassium precursor (KNO3) is dissolved in a solvent, on the resulting ruthenium/yttrium/delta-alumina material by pressurized spray at room temperature, thereby obtaining a potassium/ruthenium/yttrium/delta-alumina material;
• g) drying the potassium/ruthenium/yttrium/delta-alumina material at a temperature in a range of 100° C. to 120° C. after the supporting, followed by removing residual NO3 through firing at a temperature in a range of 500° C. to 600° C., thereby obtaining a potassium/ruthenium/yttrium/delta-alumina oxide catalyst;
• and
• h) subjecting the resulting potassium/ruthenium/yttrium/delta-alumina oxide catalyst to a rapid reduction process at a high temperature in a range of 400° C. to 500° C. using hydrogen gas, thereby preparing a final catalyst.