Shi Benjamin X, Wales David J, Michaelides Angelos, Myung Chang Woo
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
Department of Energy Science, Sungkyunkwan University, Seobu-ro 2066, Suwon 16419, Korea.
J Chem Theory Comput. 2024 Jun 25;20(12):5306-5316. doi: 10.1021/acs.jctc.4c00379. Epub 2024 Jun 10.
The structure of oxide-supported metal nanoclusters plays an essential role in their sharply enhanced catalytic activity over that of bulk metals. Simulations provide the atomic-scale resolution needed to understand these systems. However, the sensitive mix of metal-metal and metal-support interactions, which govern their structure, puts stringent requirements on the method used, requiring calculations beyond standard density functional theory (DFT). The method of choice is coupled cluster theory [specifically CCSD(T)], but its computational cost has so far prevented its application to these systems. In this work, we showcase two approaches to make CCSD(T) accuracy readily achievable in oxide-supported nanoclusters. First, we leverage the SKZCAM protocol to provide the first benchmarks of oxide-supported nanoclusters, revealing that it is specifically metal-metal interactions that are challenging to capture with DFT. Second, we propose a CCSD(T) correction (ΔCC) to the metal-metal interaction errors in DFT, reaching accuracy comparable to that of the SKZCAM protocol at significantly lower cost. This approach forges a path toward studying larger systems at reliable accuracy, which we highlight by identifying a ground-state structure in agreement with experiments for Au on MgO, a challenging system where DFT models have yielded conflicting predictions.
氧化物负载的金属纳米团簇的结构在其催化活性比块状金属大幅增强方面起着至关重要的作用。模拟提供了理解这些体系所需的原子尺度分辨率。然而，决定其结构的金属 - 金属和金属 - 载体相互作用的敏感组合，对所使用的方法提出了严格要求，需要超越标准密度泛函理论（DFT）的计算。首选方法是耦合簇理论[特别是CCSD(T)]，但其计算成本迄今为止阻碍了其在这些体系中的应用。在这项工作中，我们展示了两种方法，使CCSD(T)精度在氧化物负载的纳米团簇中易于实现。首先，我们利用SKZCAM协议提供氧化物负载纳米团簇的首个基准，揭示了用DFT捕捉金属 - 金属相互作用特别具有挑战性。其次，我们针对DFT中的金属 - 金属相互作用误差提出了一种CCSD(T)校正(ΔCC)，以显著更低的成本达到与SKZCAM协议相当的精度。这种方法为以可靠精度研究更大的体系开辟了一条道路，我们通过确定与MgO上Au的实验结果一致的基态结构来突出这一点，MgO上Au是一个具有挑战性的体系，DFT模型在该体系中给出了相互矛盾的预测。
