Single-Molecule Kinetics Reveals a Hidden Surface Reaction Intermediate in Single-Nanoparticle Catalysis
Single-Molecule Kinetics Reveals a Hidden Surface Reaction Intermediate in Single-Nanoparticle Catalysis
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DOI：
10.1021/jp509507u
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发表时间：
2014-11
影响因子：
3.7
通讯作者：
Hao Shen;Xiaochun Zhou;Ningmu Zou;Peng Chen
中科院分区：
文献类型：
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作者：
Hao Shen;Xiaochun Zhou;Ningmu Zou;Peng Chen
检测和表征反应中间体不仅对于阐明反应机制非常重要和强大，而且由于反应混合物中中间体的数量较少，因此通常也具有挑战性。研究多相催化中的表面反应中间体提出了额外的挑战，特别是催化剂颗粒之间普遍存在的结构异质性以及反应动力学中伴随的多分散性。在这里，我们使用单分子荧光显微镜以单颗粒、单周转分辨率研究两种互补类型的金纳米催化剂——介孔二氧化硅涂覆的金纳米棒（即Au@mSiO2纳米棒）和裸露的5.3 nm赝球形金纳米颗粒——在催化amplex氧化脱乙酰作用中的作用 H2O2 呈红色，这是一种与合成相关且日益重要的探针反应。对于这两种纳米催化剂，单个催化剂颗粒的微观反应时间的分布清楚地揭示了动力学中间体，它是 h...
Detecting and characterizing reaction intermediates is not only important and powerful for elucidating reaction mechanisms but also challenging in general because of the low populations of intermediates in a reaction mixture. Studying surface reaction intermediates in heterogeneous catalysis presents additional challenges, especially the ubiquitous structural heterogeneity among the catalyst particles and the accompanying polydispersion in reaction kinetics. Here we use single-molecule fluorescence microscopy to study two complementary types of Au nanocatalysts—mesoporous-silica-coated Au nanorods (i.e., Au@mSiO2 nanorods) and bare 5.3 nm pseudospherical Au nanoparticles—at the single-particle, single-turnover resolution in catalyzing the oxidative deacetylation of amplex red by H2O2, a synthetically relevant and increasingly important probe reaction. For both nanocatalysts, the distributions of the microscopic reaction time from a single catalyst particle clearly reveal a kinetic intermediate, which is h...