14574
The electrochemical oxygen reduction reaction ( ORR ) on a n - Ge ( 100 ) surface in 0 . 1 M HClO4 was investigated in situ and operando using a combination of attenuated total reflection infrared ( ATR - IR ) spectroscopy and density functional ( DFT ) calculations .
 Chemical: oxygen; Chemical: Ge; Chemical: HClO4
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: oxygen; Chemical: Ge; Chemical: HClO4