13103
ZnO is a CO ( 2 ) - selective steam reforming catalyst .
 Chemical: ZnO; Chemical: CO ( 2 )
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: ZnO; Chemical: CO ( 2 )