Ammonia decomposition catalyst and ammonia decomposition method thereby

The present invention discloses a catalyst suitable for contact decomposition of high concentration ammonia and the ammonia decomposition method using the catalyst. The ammonia decomposition catalyst having Si/Al (atomic ratio) within 1 to 90 is formed by using ion exchange method to support the metal elements of Group 8 to 12 in the periodic table onto porous silica alumina with specific surface area 200 to 900 m2/g and then burning the supported porous silica alumina.