24901
In Situ Study of CO Oxidation on HOPG - Supported Pt Nanoparticles .
 Chemical: CO; Chemical: Pt
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: CO, Pt 
Answer:
 Chemical: CO; Chemical: Pt