| 초록 |
The redox catalytic properties of carbons have been investigated due to fundamental interests and possible practical applications. Although various carbons are available, the effects of nanostructures on their redox properties have not been understood. In this work, the redox properties and thermochemical stabilities of sixteen carbons were investigated using oxidative dehydrogenation. Regardless of the carbon types, the activity increased with the content of C=O active sites. However, with increasing C=O content, the activity per site gradually decreased while the alkene selectivity increased due to the lower reducibility of the carbon. Because more C=O sites are present in a less stable edge sites, the carbons generally showed a trade-off relationship between activity and stability. However, a graphitic carbon with a ‘coin-stacking’ of the carbon layers showed an exceptionally high activity and stability due to the unique structure that simultaneously provides a high graphitic order and abundant edge sites. The understanding of the correlation between the nanostructures and redox properties/stability can provide important insights into the design of advanced carbon catalysts. |
