Graph theory approach to determine configurations of multidentate and high coverage adsorbates for heterogeneous catalysis
Graph theory approach to determine configurations of multidentate and high coverage adsorbates for heterogeneous catalysis
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DOI：
10.1038/s41524-020-0345-2
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发表时间：
2020-06-18
影响因子：
9.7
通讯作者：
Greeley, Jeffrey
中科院分区：
文献类型：
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作者：
Deshpande, Siddharth;Maxson, Tristan;Greeley, Jeffrey
非均相催化剂是许多工业过程的重要组成部分，为了理解这些催化剂的原子尺度特征，从头算密度泛函理论被广泛采用。最近，不断增长的计算能力已经允许扩展这些研究复杂的反应网络，涉及高吸附物覆盖率或多齿吸附物，通过多个原子结合到表面。然而，仅仅基于化学直觉，描述这种系统的所有可能的吸附物构型通常是不可能的。为了系统地处理这种复杂性，我们提出了一种基于Python的广义图论方法，将原子尺度模型转换为无向图表示。这些表示，当与工作流程，如进化算法相结合，可以系统地生成高覆盖率的吸附物模型，并分类独特的最小能量多齿吸附物配置的低对称性的表面，包括多元素合金表面，步骤和扭结。两个案例研究证明了这些能力，第一，分析的覆盖率依赖的相图的Pt3Sn（111）平台表面上，和第二，吸附能的调查，连同确定独特的最低能量配置，为反应中间体丙炔（CHCCH 3 *）吸附在PdIn（021）台阶表面。进化算法方法仅使用蛮力方法所需的模拟次数的15%再现了Pt 3Sn（111）上NO的高覆盖配置。此外，潜在的数百个多齿吸附物的筛选被证明是可能的，没有人为干预。所提出的策略是相当普遍的，可以应用到复杂的原子系统的光谱。
Heterogeneous catalysts constitute a crucial component of many industrial processes, and to gain an understanding of the atomic-scale features of such catalysts, ab initio density functional theory is widely employed. Recently, growing computational power has permitted the extension of such studies to complex reaction networks involving either high adsorbate coverages or multidentate adsorbates, which bind to the surface through multiple atoms. Describing all possible adsorbate configurations for such systems, however, is often not possible based on chemical intuition alone. To systematically treat such complexities, we present a generalized Python-based graph theory approach to convert atomic scale models into undirected graph representations. These representations, when combined with workflows such as evolutionary algorithms, can systematically generate high coverage adsorbate models and classify unique minimum energy multidentate adsorbate configurations for surfaces of low symmetry, including multi-elemental alloy surfaces, steps, and kinks. Two case studies are presented which demonstrate these capabilities; first, an analysis of a coverage-dependent phase diagram of absorbate NO on the Pt3Sn(111) terrace surface, and second, an investigation of adsorption energies, together with identifying unique minimum energy configurations, for the reaction intermediate propyne (CHCCH3*) adsorbed on a PdIn(021) step surface. The evolutionary algorithm approach reproduces high coverage configurations of NO on Pt3Sn(111) using only 15% of the number of simulations required for a brute force approach. Furthermore, the screening of potentially hundreds of multidentate adsorbates is shown to be possible without human intervention. The strategy presented is quite general and can be applied to a spectrum of complex atomic systems.