Composite catalyst for hydrogen selective catalytic reduction, method of removing nitrogen oxides using the same, and air purification device including composite catalyst

A method of removing nitrogen oxides, the method comprising:

• contacting an air stream including nitrogen oxides with a composite catalyst for hydrogen-selective catalytic reduction to remove nitrogen oxides,
• wherein the composite catalyst comprises:
• a support;
• and
• catalyst composite particles supported on the support,
• wherein the catalyst composite particles comprise platinum and a group 6 element oxide, and
• a content of the group 6 element oxide is about 0.1 parts by weight to about 5 parts by weight with respect to 1 part by weight of a content of the platinum.

An air purification device comprising:

• a housing;
• and
• a composite catalyst for hydrogen-selective catalytic reduction,
• wherein the composite catalyst is located within the housing, and
• wherein the composite catalyst for hydrogen-selective catalytic reduction is configured to remove a contaminant compound from an unpurified air stream containing the contaminant compound, and comprises:
• a support;
• and catalyst composite particles supported on the support,
• wherein the catalyst composite particles comprise platinum and a group 6 element oxide, and
• a content of the group 6 element oxide is about 0.1 parts by weight to about 5 parts by weight with respect to 1 part by weight of a content of the platinum.