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Furthermore , compared with highly active IrO ( 2 ) , the improved durability , precious - metal Ir utilization efficiency and correspondingly reduced Ir loading were realized by the addition of Sn component .
 IrO ( 2 ), Ir, Ir, Sn
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 IrO ( 2 ), Ir, Ir, Sn