Differences in intermediate structures and electronic states associated with oxygen adsorption onto Pt, Cu, and Au clusters as oxygen reduction catalysts
Differences in intermediate structures and electronic states associated with oxygen adsorption onto Pt, Cu, and Au clusters as oxygen reduction catalysts
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DOI：
10.1088/0022-3727/49/41/415305
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发表时间：
2016-09
期刊：
影响因子：
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通讯作者：
Tetsunori Morishita;T. Ueno;G. Panomsuwan;J. Hieda;M. Bratescu;N. Saito
中科院分区：
文献类型：
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作者：
Tetsunori Morishita;T. Ueno;G. Panomsuwan;J. Hieda;M. Bratescu;N. Saito
我们使用从头计算的分子轨道（MO）研究的中间结构和电子状态的差异参与吸附O2到13个原子的金属团簇的Pt，Cu，和Au。此外，对Pt、Cu和Au团簇上的电催化氧还原反应（ORR）所需的条件进行了研究和讨论。O2在Pt、Cu和Au上吸附的中间产物分别为（Pt-O）-（Pt-O）、Cu-O和Au-O2。O2吸附中间体的差异解释的基础上，我们分析的投影态密度（PDOS）面积的新MO从O2的2 p π* 轨道和d轨道的金属团簇的混合物产生的。O2吸附到Pt团簇上后形成的（Pt-O）-（Pt-O）中间体是由于费米能级以上的反键轨道的出现。因此，这种电子状态可以导致O2分子的分解和解吸，从而促进ORR的高活性水平。对于Cu团簇，在费米能级以下观察到一个新的反键轨道。此外，Cu团簇表面只能促进O2的分解，而不是O2的解吸，由于形成的铜氧化物。对于Au簇，由于O2被分子吸附，没有出现与O2的2 p π* 轨道相关的新MO，这意味着Au簇是低效的ORR催化剂。
We used ab initio molecular orbital (MO) calculations to study the differences in the intermediate structures and the electronic states involved in the adsorption of O2 onto 13-atom metal clusters of Pt, Cu, and Au. Additionally, the conditions required for the electrocatalytic oxygen reduction reaction (ORR) on the Pt, Cu, and Au clusters were investigated and discussed. The intermediates involved in O2 adsorption onto Pt, Cu, and Au were found to be (Pt–O)–(Pt–O), Cu–O, and Au–O2, respectively. The differences in the O2 adsorption intermediates is explained on the basis of our analysis of the projected density of state (PDOS) area of the new MOs produced from a mixture of the 2pπ* orbitals of O2 and the d orbitals of the metal clusters. The formation of the (Pt–O)–(Pt–O) intermediate after the adsorption of O2 onto the Pt cluster is attributed to the emergence of an antibonding orbital above the Fermi level. Thus, this electronic state can lead to the decomposition and desorption of O2 molecules, thereby promoting the high-activity level of ORR. For the Cu cluster, a new antibonding orbital was observed below the Fermi level. Moreover, the Cu cluster surface can only promote O2 decomposition and not O2 desorption due to the formation of copper oxides. For the Au cluster, no new MOs related to 2pπ* orbitals of O2 appeared because O2 was molecularly adsorbed, implying that the Au cluster is an inefficient ORR catalyst.