Atomic-Scale Mechanism of Platinum Catalyst Restructuring under a Pressure of Reactant Gas
Atomic-Scale Mechanism of Platinum Catalyst Restructuring under a Pressure of Reactant Gas
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反应气体压力下铂催化剂重构的原子尺度机理
DOI：
10.1021/jacs.2c10179
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发表时间：
2022
影响因子：
15
通讯作者：
Sautet, Philippe
中科院分区：
文献类型：
--
作者：
Sumaria, Vaidish;Nguyen, Luan;Tao, Franklin Feng;Sautet, Philippe
多相催化是化学转化的关键。了解催化剂的活性位点在反应条件下如何在原子尺度上动态演化是准确确定催化机理和可预测地开发催化剂的先决条件。我们结合现场时间依赖的扫描隧道显微镜观察和机器学习加速的第一性原理原子模拟，揭示了铂催化剂在一氧化碳（CO）压力下重组的机制。我们发现，在铂台阶边缘的高CO覆盖率触发了低配位铂原子的原子突起的形成，然后这些原子从台阶边缘分离出来，在阶地上形成亚纳米岛，其中CO吸附物稳定了低配位的位置。快速准确的机器学习潜力是探索co覆盖重组催化剂数万种构型的关键。这些研究为在反应条件下实现对更复杂的金属纳米颗粒催化剂结构动力学的原子尺度理解开辟了一条途径。
Heterogeneous catalysis is key for chemical transformations. Understanding how catalysts’ active sites dynamically evolve at the atomic scale under reaction conditions is a prerequisite for accurately determining catalytic mechanisms and predictably developing catalysts. We combine in situ time-dependent scanning tunneling microscopy observations and machine-learning-accelerated first-principles atomistic simulations to uncover the mechanism of restructuring of Pt catalysts under a pressure of carbon monoxide (CO). We show that a high CO coverage at a Pt step edge triggers the formation of atomic protrusions of low-coordination Pt atoms, which then detach from the step edge to create sub-nano-islands on the terraces, where under-coordinated sites are stabilized by the CO adsorbates. The fast and accurate machine-learning potential is key to enabling the exploration of tens of thousands of configurations for the CO-covered restructuring catalyst. These studies open an avenue to achieve an atomic-scale understanding of the structural dynamics of more complex metal nanoparticle catalysts under reaction conditions.