21031
The three factors work together , leading to superb electrochemical catalytic activities for both hydrazine oxidation ( its current generation ability is comparable to that of 10 wt % Pt - C catalyst ) and oxygen reduction ( its limiting current is comparable to that of 20 wt % Pt - C catalyst ) with four - electron transfer processes and excellent durability .
 Chemical: hydrazine; Chemical: Pt; Chemical: C; Chemical: oxygen; Chemical: Pt; Chemical: C
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: hydrazine, Pt, C, oxygen, Pt, C 
Answer:
 Chemical: hydrazine; Chemical: Pt; Chemical: C; Chemical: oxygen; Chemical: Pt; Chemical: C