Interactions of Au cluster anions with oxygen.
Interactions of Au cluster anions with oxygen.
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DOI：
10.1063/1.1666009
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发表时间：
2004-03
期刊：
影响因子：
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通讯作者：
Qiang Sun;P. Jena;Y. D. Kim;M. Fischer;G. Ganteför
中科院分区：
文献类型：
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作者：
Qiang Sun;P. Jena;Y. D. Kim;M. Fischer;G. Ganteför
实验和理论证明了O_2在自由Au团簇阴离子（Aun-，n=原子数）（n=2，4，6）上的非解离化学吸附，表明活性双氧物种的稳定性是Au基催化剂不同寻常的催化活性的关键.与Aun-（n=2，4，6）相反，O2以原子形式吸附在Au单体阴离子上.对于Au单体中性，基于密度泛函理论的计算表明，氧应该是分子结合的。在Au二聚体和四聚体中性，氧是分子结合的O-O键被激活相对于其阴离子对应物，这表明在阴离子状态的过剩电子起着至关重要的作用的O-O激活。我们表明，气相簇实验和理论方法之间的相互作用可以是一个很有前途的策略，揭示纳米催化的基本步骤的机制。
Experimental and theoretical evidence is presented for the nondissociative chemisorption of O2 on free Au cluster anions (Aun-, n=number of atoms) with n=2, 4, 6 at room temperature, indicating that the stabilization of the activated di-oxygen species is the key for the unusual catalytic activities of Au-based catalysts. In contrast to Aun- with n=2, 4, 6, O2 adsorbs atomically on Au monomer anions. For the Au monomer neutral, calculations based on density functional theory reveal that oxygen should be molecularly bound. On Au dimer and tetramer neutrals, oxygen is molecularly bound with the O-O bond being less activated with respect to their anionic counterparts, suggesting that the excess electron in the anionic state plays a crucial role for the O-O activation. We demonstrate that interplay between experiments on gas phase clusters and theoretical approach can be a promising strategy to unveil mechanisms of elementary steps in nanocatalysis.