Wei Guang-Feng, Liu Zhi-Pan
Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials , Department of Chemistry , Key Laboratory of Computational Physical Science (Ministry of Education) , Fudan University , Shanghai 200433 , China . Email:
Chem Sci. 2015 Feb 1;6(2):1485-1490. doi: 10.1039/c4sc02806f. Epub 2014 Nov 26.
The restructuring of nanoparticles at the condition is a common but complex phenomenon in nanoscience. Here, we present the first systematic survey on the structure dynamics and its catalytic consequence for hydrogen evolution reaction (HER) on Pt nanoparticles, as represented by a magic number Pt octahedron (∼1 nm size). Using a first principles calculation based global structure search method, we stepwise follow the significant nanoparticle restructuring under HER conditions as driven by thermodynamics to expose {100} facets, and reveal the consequent large activity enhancement due to the marked increase of the concentration of the active site, being identified to be apex atoms. The enhanced kinetics is thus a "byproduct" of the thermodynamical restructuring. Based on the results, the best Pt catalyst for HER is predicted to be ultrasmall Pt particles without core atoms, a size below ∼20 atoms.
在该条件下纳米颗粒的重构是纳米科学中一种常见但复杂的现象。在此，我们首次对以具有幻数的铂八面体（尺寸约为1 nm）为代表的铂纳米颗粒上析氢反应（HER）的结构动力学及其催化结果进行了系统研究。使用基于第一性原理计算的全局结构搜索方法，我们逐步追踪了在HER条件下由热力学驱动的显著纳米颗粒重构，以暴露出{100}面，并揭示了由于活性位点（被确定为顶点原子）浓度的显著增加而导致的活性大幅增强。因此，增强的动力学是热力学重构的“副产品”。基于这些结果，预测用于HER的最佳铂催化剂是没有核心原子的超小铂颗粒，尺寸小于约20个原子。
