CAJ | 학술논문

采用密度泛函理论中的B3LYP方法研究了H2在AlnCr(n=1-7)团簇上的吸附和解离。结果表明：Aln Cr团簇结构与Aln+1团簇结构相似；物理吸附是H2以侧向的形式吸附在Cr原子上,H-H键长略微增长,H2的振动频率发生了红移；除了n=5外,其它Aln CrH2团簇的最稳定结构均是Aln Cr团簇的最稳定结构与两个氢原子成键而成；Aln Cr团簇向H原子转移了电荷；Aln CrH2团簇的平均结合能,垂直电离势和能隙均大于Aln Cr团簇的,即Aln CrH2团簇比Aln Cr团簇更稳定；Al7 Cr对H2的化学吸附表现出较强的惰性,而AlnCrH2(n=1,2,6)则表现出较强的化学活性；由化学反应路径跟踪可知,通过改变AlnCr团簇中Al原子的个数可以调节H2的物理化学吸附行为。
채용밀도범함이론중적B3LYP방법연구료H2재AlnCr(n=1-7)단족상적흡부화해리。결과표명：Aln Cr단족결구여Aln+1단족결구상사；물리흡부시H2이측향적형식흡부재Cr원자상,H-H건장략미증장,H2적진동빈솔발생료홍이；제료n=5외,기타Aln CrH2단족적최은정결구균시Aln Cr단족적최은정결구여량개경원자성건이성；Aln Cr단족향H원자전이료전하；Aln CrH2단족적평균결합능,수직전리세화능극균대우Aln Cr단족적,즉Aln CrH2단족비Aln Cr단족경은정；Al7 Cr대H2적화학흡부표현출교강적타성,이AlnCrH2(n=1,2,6)칙표현출교강적화학활성；유화학반응로경근종가지,통과개변AlnCr단족중Al원자적개수가이조절H2적물이화학흡부행위。
The adsorption and dissociation of molecular hydrogen on AlnCr(n=1-7) clusters are investigated by using the method of B3LYP in density functional theory. The results show that the structures of AlnCr clusters are similar to those of Aln+1 clusters. H2 is easily adsorbed physically on Cr atom with a side-on orientation. The bond length of H-H increases slightly. The vibration frequency of H2 adsorbed is smaller than that of free molecular H2, namely, a red-shift occurs. Except for n=5, the most stable structures of the other AlnCrH2 clusters are composed by the most stable structures of AlnCr clusters and two H atoms. Charge transfers from AlnCr clusters to H atoms. Average binding energy, vertical ionization potential and energy gap of AlnCrH2 clus-ters are all greater than those of AlnCr clusters, namely AlnCrH2 clusters are more stable than AlnCr clusters. Al7Cr cluster shows stronger inertness for chemical adsorption of H2, while AlnCrH2(n=1,2,6) show stronger chemical activity. The physical and chemical adsorption behavior of H2 on AlnCr clusters can be adjusted by changing the number of Al atom in AlnCr clusters from tracking the chemical reaction path.