Patent ID: 11918981
Assignee: INDUSTRY FOUNDATION OF CHONNAM NATIONAL UNIVERSITY
Field: Chemical engineering (Chemistry)
Classification: CPC B  C | IPC B  C

Claim 4:
5. A method for producing a multicomponent metal oxide catalyst having a perovskite lattice structure, the method comprising:
a step of mixing and stirring a first metal precursor, citric acid, and ethylene glycol at a molar ratio of 0.1:0.4:0.9 in distilled water in a temperature range of 50 to 90° C., thereby preparing a first mixture solution;
a step of mixing and stirring a titanium precursor and a second metal precursor in anhydrous ethanol in a temperature range of 50 to 90° C., thereby preparing a second mixture solution;
a reaction step of mixing the first mixture solution and the second mixture solution, followed by stirring in a temperature range of 50 to 90° C. for about 24 hours;
a step of removing the solvent through a drying step after the reaction step;
a first calcination step of calcining a solid-state material, obtained through the drying step, in a temperature range of about 300 to 400° C. with a highest temperature keeping time of 5 hours under an oxygen atmosphere; and
a second calcination step of calcining the solid-state material in a temperature range of about 800 to 1,000° C. with a highest temperature keeping time of 5 hours under an oxygen atmosphere after the first calcination step,
wherein the first calcination is performed with a temperature-rising time of 70 minutes and a temperature-maintaining time of 5 hours, and
the second calcination is performed with a temperature-rising time of 4 hours and a temperature-maintaining time of 5 hours,
wherein the ratio of the sum of the moles of Ti and the second metal, which are contained in the titanium precursor and the second metal precursor, respectively, to the moles of the first metal contained in the first metal precursors, is maintained at 1:1, so that the second metal in ionic form is substituted in the perovskite lattice structure,
the first metal precursor is strontium nitrate, magnesium nitrate, calcium nitrate, or barium nitrate, and
the second metal precursor is a nickel precursor,
wherein,
the multicomponent metal oxide catalyst has a perovskite structure,
the multicomponent metal oxide catalyst is MgTiO3, CaTiO3, BaTiO3, or SrTiO3, wherein the Ti site of the MgTiO3, CaTiO3, BaTiO3, or SrTiO3 is partially substituted with an ionic form of Ni,
the multicomponent metal oxide catalyst has no nickel oxide (NiO), and
the multicomponent metal oxide catalyst is represented by the following Formula (1):

MTi1-xNixO3-δ  Formula (1)

wherein x is 0<x<0.03, δ is 0<δ<0.10, and M is Sr, Mg, Ca, or Ba,
wherein the ionic form of Ni has a coordination number lower than six and an oxidation number of +2, and δ is determined to maintain neutrality of the multicomponent metal oxide catalyst.