11115
Some perovskites exhibited an apparent negative activation energy for k * , the behavior of which is explained by a precursor - mediated mechanism for dissociative adsorption .
 Chemical: perovskites
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: perovskites