CPC B01J 37/0221 (2013.01) [B01J 21/18 (2013.01); B01J 23/42 (2013.01); B01J 23/75 (2013.01); B01J 23/755 (2013.01); B01J 23/892 (2013.01); B01J 23/8913 (2013.01); B01J 35/002 (2013.01); B01J 35/008 (2013.01); B01J 35/0013 (2013.01); B01J 35/02 (2013.01); B01J 37/08 (2013.01); B01J 37/16 (2013.01); B01J 37/343 (2013.01); H01M 4/92 (2013.01)] | 4 Claims |
1. A method for preparing a liquid-nitridation treated core-shell catalyst, the method comprising the steps of:
irradiating ultrasonic waves to a solution including liquid-urea as a nitrogen source, a reducing solvent, a noble metal precursor, a transition metal precursor and a carbon support at 150 to 200° C.; and
forming a cavity and forming transition metal precursor core and noble metal precursor shell particles due to a difference in vapor pressures while nitridation treating the transition metal precursor by combining with liquid-urea, to prepare a core-shell catalys, wherein
a nitrogen atom is maintained in a molar ratio 10.5 to 41.1 moles per 58.9 to 89.5 moles of the transition metal,
an average particle diameter of the prepared core-shell catalyst is 4.0 nm or less,
the transition metal precursor is at least one kind selected from the group consisting of an acethylacetonate precursor of the transition metal and a hexafluoroacetylacetonate precursor of the transition metal,
the noble metal precursor is at least one kind selected from the group consisting of an acetylacetonate precursor of the noble metal, a hexafluoroacetylacetonate precursor of the noble metal and pentafluoroacetylacetonate precursor of the noble metal, and
the reducing solvent has a reducing power at a high temperature of 70° C. or higher, and is at least one kind of ethylene glycols selected from the group consisting of di-ethylene glycol, tri-ethylene glycol and poly-ethylene glycol.
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