16450
Of the small clusters , only a few cluster sizes show the expected ORR activity , and in those cases , the activity per Pt atom is similar to that seen under identical conditions with a conventionally prepared electrode with Pt nanoparticles grown on a GCE .
 Chemical: Pt; Chemical: Pt
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: Pt; Chemical: Pt