Efficient Synthesis of Endohedral Metallofullerenes in 3-Phase Arc Discharge

Abstract

Endohedral metallofullerenes and, in particular, trimetallic nitride endohedral metallofullerenes exhibit unique properties that differentiate them from other carbon nanomaterials. Future applications of these species are restricted due to high cost and low productivity of existing synthesis methods, which are primarily based on the use of a Krätschmer-Huffman two electrode in-line arc discharge reactor with packed electrodes. We have developed an alternative way for the synthesis of metallofullerenes that employs a 3-phase arc discharge system. The method has been validated and optimized for the synthesis of trimetallic nitride endohedral metallofullerenes, including Lu3N@C80. Experimental results have shown more than 400% increase in Lu3N@C80 yield and productivity, while eliminating the use of high cost process gases (i.e., helium). Moreover, a metal oxide powder feed and solid graphite electrodes are introduced to avoid the need for packed electrodes and to extend reactor run times.