超碱NLi_(4)团簇修饰DHQ石墨烯的储氢性能研究

Hydrogen storage property of superalkali NLi_(4) decorated DHQ-graphene

基于第一性原理计算,系统研究了超碱NLi_(4)团簇修饰在DHQ石墨烯表面上的几何结构及吸附能等性质,并深入探索了其储氢性能.研究结果表明:超碱NLi_(4)团簇可以稳定均匀地吸附在DHQ石墨烯表面,Li原子与N原子的强结合能有效避免了Li原子发生团聚.每个NLi_(4)团簇周围最多可吸附11个氢气分子,平均吸附能为0.20 eV,最大储氢容量为12.05 wt%,达到美国能源部制定的2025年储氢目标5.5 wt%.最后,基于相对能量计算,发现当压强大于84 bar时,该储氢体系可以在室温下稳定存在.以上结果表明经超碱NLi_(4)团簇修饰的DHQ石墨烯是一种有潜力的储氢材料.

Based on the first-principles calculations,the structure and adsorption energy of superalkali NLi_(4)decorated DHQ-graphene are studied systematically,and its hydrogen storage performance is further explored.The results show that superalkali NLi_(4)can adsorb on the surface of DHQ-graphene stably and uniformly,the strong binding energy between Li atoms and N atoms effectively avoids the formation of Li atom clusters.Each NLi_(4)can physically adsorb up to 11 hydrogen molecules with the average adsorption energy of 0.20 eV.The maximum hydrogen storage capacity is 12.05 wt%,reaching the US Department of Energy's 2025 hydrogen storage target of 5.5 wt%.Furthermore,through relative energy calculations,it is found that the hydrogen storage system can remain stable at room temperature when the pressure is greater than 84 bar.The above results indicate that superalkali NLi_(4)decorated DHQ-graphene is a promising hydrogen storage material.