Single d-metal atoms on F(s) and F(s+) defects of MgO(001): a theoretical study across the periodic table.
Single d-metal atoms on F(s) and F(s+) defects of MgO(001): a theoretical study across the periodic table.
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DOI：
10.1021/ja052437i
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发表时间：
2005-07
影响因子：
15
通讯作者：
Konstantin M. Neyman;Chan Inntam;A. Matveev;V. Nasluzov;N. Rösch
中科院分区：
文献类型：
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作者：
Konstantin M. Neyman;Chan Inntam;A. Matveev;V. Nasluzov;N. Rösch
对MgO（001）表面氧缺陷F（s）和F（s+）上的单个d-金属原子进行了理论研究。我们采用了一个精确的密度泛函方法结合集群模型，嵌入在一个弹性极化的环境中，我们应用了两个梯度校正的交换相关泛函。以这种方式，我们量化了来自周期表第6-11族的17种金属原子（Cu、Ag、Au; Ni、Pd、Pt; Co、Rh、Ir; Fe、Ru、Os; Mn、Re;以及Cr、Mo、W）如何与MgO的平台位点相互作用。我们发现，与F（s）和F（s+）缺陷的键合一般比与O2-位的键合强，除了Mn-，Re-和Fe/F（s）络合物。在M/F（s）系统中，电子密度以显著的方式积累在金属中心上。这两种O缺陷的结合能从3d-到4d-到5d-原子增加，与之前建立的M/O 2-复合物的结合能趋势不同，4d < 3d < 5d。关于结合能沿着一个周期的演变，在F（s）和F（s+）络合物中，与它们的6族同源物相比，7族原子略微不稳定;对于稍后的过渡元素，结合能逐渐增加到10族，最后在11族中再次降低，在F（s）位点上最强烈。这种趋势是由吸附原子上的负电荷决定的。我们讨论了实验检测的金属原子氧化物支持计算的核心水平的能量的基础上的影响。
Single d-metal atoms on oxygen defects F(s) and F(s+) of the MgO(001) surface were studied theoretically. We employed an accurate density functional method combined with cluster models, embedded in an elastic polarizable environment, and we applied two gradient-corrected exchange-correlation functionals. In this way, we quantified how 17 metal atoms from groups 6-11 of the periodic table (Cu, Ag, Au; Ni, Pd, Pt; Co, Rh, Ir; Fe, Ru, Os; Mn, Re; and Cr, Mo, W) interact with terrace sites of MgO. We found bonding with F(s) and F(s+) defects to be in general stronger than that with O2- sites, except for Mn-, Re-, and Fe/F(s) complexes. In M/F(s) systems, electron density is accumulated on the metal center in a notable fashion. The binding energy on both kinds of O defects increases from 3d- to 4d- to 5d-atoms of a given group, at variance with the binding energy trend established earlier for the M/O2- complexes, 4d < 3d < 5d. Regarding the evolution of the binding energy along a period, group 7 atoms are slightly destabilized compared to their group 6 congeners in both the F(s) and F(s+) complexes; for later transition elements, the binding energy increases gradually up to group 10 and finally decreases again in group 11, most strongly on the F(s) site. This trend is governed by the negative charge on the adsorbed atoms. We discuss implications for an experimental detection of metal atoms on oxide supports based on computed core-level energies.