奥地利应用物理研究所Gareth S. Parkinson团队揭示了模型单原子催化剂上CO吸附机制。相关研究成果发表在2021年1月22日出版的《科学》。

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。

研究人员对Fe3O4（001）上的铜₁、银₁、金₁、镍₁、钯₁、铂₁、铑₁和铱₁物种进行了深入研究，Fe3O4（001）是一种模型载体，所有金属在室温下沉积时占据相同的双配位吸附位。表面科学技术表明，CO在单个金属表面的吸附强度不同于相应的金属表面和负载团簇。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Ag₁–CO）或削弱键（如Ni₁–CO），但CO引起的结构扭曲会降低吸附能，而不是仅基于电子结构的预期吸附能。弛豫的程度取决于局部几何结构，可以用配位化学的类比来预测。

附：英文原文

Title: Unraveling CO adsorption on model single-atom catalysts

Author: Jan Hulva, Matthias Meier, Roland Bliem, Zdenek Jakub, Florian Kraushofer, Michael Schmid, Ulrike Diebold, Cesare Franchini, Gareth S. Parkinson

Issue&Volume: 2021/01/22

Abstract: Understanding how the local environment of a “single-atom” catalyst affects stability and reactivity remains a challenge. We present an in-depth study of copper1, silver1, gold1, nickel1, palladium1, platinum1, rhodium1, and iridium1 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 Ag1–CO) or weaken it (as for Ni1–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.

DOI: 10.1126/science.abe5757

Source: https://science.sciencemag.org/content/371/6527/375