Unraveling CO adsorption on model single-atom catalysts
Unraveling CO adsorption on model single-atom catalysts
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DOI：
10.1126/science.abe5757
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发表时间：
2021-01-22
期刊：
影响因子：
56.9
通讯作者：
Parkinson, Gareth S.
中科院分区：
文献类型：
--
作者：
Hulva, Jan;Meier, Matthias;Parkinson, Gareth S.
理解“单原子”催化剂的局部环境如何影响稳定性和反应性仍然是一个挑战。我们研究了铜(1)、银(1)、金(1)、镍(1)、钯(1)、铂(1)、铑(1)和铱(1)在Fe_3O_4(001)上的吸附行为。表面科学技术表明，CO在单个金属位置上的吸附强度不同于相应的金属表面和负载的团簇。电荷转移到载体上改变了金属原子的d态和金属-CO键的强度。这些效应可以加强键(如Ag-1-CO)或削弱键(如Ni-1-CO)，但CO引起的结构扭曲降低了吸附能，而不是仅基于电子结构的吸附能。弛豫的程度取决于局部几何结构，可以用配位化学类比来预测。
Understanding how the local environment of a "single-atom" catalyst affects stability and reactivity remains a challenge. We present an in-depth study of copper(1), silver(1), gold(1), nickel(1), palladium(1), platinum(1), rhodium(1), and iridium(1) species on Fe3O4(001), a model support in which all metals occupy the same twofold-coordinated adsorption site upon deposition at room temperature. Surface science techniques revealed that CO adsorption strength at single metal sites differs from the respective metal surfaces and supported clusters. Charge transfer into the support modifies the d-states of the metal atom and the strength of the metal-CO bond. These effects could strengthen the bond (as for Ag-1-CO) or weaken it (as for Ni-1-CO), but CO-induced structural distortions reduce adsorption energies from those expected on the basis of electronic structure alone. The extent of the relaxations depends on the local geometry and could be predicted by analogy to coordination chemistry.