13241
When the Ir ( 0 . 52 ) Sn ( 0 . 48 ) O ( 2 ) cell operated at 80 degrees C using Nafion (R) 115 membrane and less than 0 . 8 mg cm ( - 2 ) of the noble - metal Ir loading , the cell voltages we achieved were 1 . 631 V at 1000 mA cm ( - 2 ) , and 1 . 821 V at 2000 mA cm ( - 2 ) .
 Ir, Sn, O ( 2 ), Nafion, Ir
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Ir, Sn, O ( 2 ), Nafion, Ir