4552
More interestingly , when catalytically active Pt nanocrystals were introduced into the manganese oxide / silica system , the Mn ( 3 ) O ( 4 ) was readily reduced to the chemically reactive MnO , even at low temperature , which enabled reconversion of the solid nanospheres with a Mn ( 3 ) O ( 4 ) core to hollow nanostructures during reductive annealing .
 Chemical: Pt; Chemical: manganese oxide; Chemical: silica; Chemical: Mn ( 3 ) O ( 4 ); Chemical: MnO; Chemical: Mn ( 3 ) O ( 4 )
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: Pt; Chemical: manganese oxide; Chemical: silica; Chemical: Mn ( 3 ) O ( 4 ); Chemical: MnO; Chemical: Mn ( 3 ) O ( 4 )