本論文利用理論計算研究鹼金屬(鋰、鈉、鉀)修飾之芳香碳環分子(苯環、蒄環),探討其應用在儲存氫氣載體之可能性。我們主要利用B3LYP/6-311++g(2d,2p) 和MP2/6-311++g(2d,2p)兩個方法進行計算。為了增強金屬與碳環分子間的鍵結能力,我們的策略是利用摻雜硼或氮原子來進行芳香環碳上的取代作用。本篇的計算結果發現,由於電荷轉移在氫氣吸附過程中扮演重要角色,因此碳環分子處於電中性或是帶電荷兩種不同情況時,在儲氫表現上會有明顯的差異,當系統處於帶電荷狀態(金屬游離)儲氫效能較佳。最後,本論文所研究的儲氫系統,最高儲氫比例可達11.85 wt %,已滿足美國能源局所訂定的目標值。盼望本論文提供的資訊能有助於未來延伸到石墨烯系統上的儲氫研究。
We report a computational study on hydrogen storage media consisting of alkali-metal (Li, Na, K, Li+, Na+, K+) atom and aromatic carbon ring based (benzene, coronene) molecular materials. We use two major and reliable computational method: B3LYP/6-311++g(2d,2p) & MP2/6-311++g(2d,2p) to calculate our materials. Doping some boron or nitrogen atoms into carbon ring is our strategy to enhance the bonding ability between metal and carbon ring. Our calculations show that the systems with positive charge are better than neutral on hydrogen adsorption process because of its charge transfer. Finally, according to our calculations, the maximum hydrogen storage capacity can reach 11.85 wt %, it has already shoot the target of U.S. DoE. In the future, we hope the information will be useful for extending the study of graphene-based system for hydrogen storage.