20085
In comparison with previously reported nickel - based catalysts , the Ru / C catalyst is advantageous because it is highly active ( as low as 360 ppm Ru ) and recyclable .
 Chemical: nickel; Chemical: Ru; Chemical: C; Chemical: Ru
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: nickel; Chemical: Ru; Chemical: C; Chemical: Ru