In situ label-free monitoring of noble metal nanoparticle-catalyzed reactions using surface-enhanced Raman spectroscopy: correlative single particle studies and mechanistic investigations

贵金属纳米颗粒是许多化学反应的重要催化剂。表面增强拉曼散射（SERS）能够以无标记的方式原位探测潜在的分子转化，具有高化学特异性、高灵敏度和界面选择性。在这份NSFC/DFG联合提案中，来自中国（Xie）和德国（schl<e:1> cker）的申请人希望继续他们现有的成功合作，并结合他们的专业知识，研究使用氢化物和分子氢作为还原剂在金、铂和钯纳米颗粒表面的硝基到氨基转化。将合成多种具有SERS和催化活性的双功能贵金属核心/卫星纳米颗粒（Xie实验室），并在定制的反应器中进行相关的单粒子水平SERS光谱/电镜实验（schl<e:1> cker实验室）。通过合成和研究一组合理设计的具有不同位置硝基的educt分子（Xie实验室），我们希望获得对硝基到氨基转化如何发生的机制理解。最后，高分辨率SERS光谱（Xie实验室）结合相应的DFT计算（schl<e:1> cker实验室）旨在解析微流控反应器中相应的反应中间体。

Noble metal nanoparticles are important catalysts for many chemical reactions. Surface-enhanced Raman scattering (SERS) is capable of in situ probing the underlying molecular transformations in a label-free manner with high chemical specificity, high sensitivity, and interface selectivity. In this joint NSFC/DFG proposal, the applicants from China (Xie) and Germany (Schlücker) want to continue their existing successful collaboration and to combine their expertise for investigating the nitro-to-amino conversion on the surface of gold, platinum, and palladium nanoparticles using hydride and molecular hydrogen as reducing agents. Various bifunctional noble metal core/satellite nanoparticles with both SERS and catalytic activity will be synthesized (Xie lab) and characterized in correlative SERS spectroscopic/electron microscopic experiments at the single-particle level in custom-made reactors (Schlücker lab). By synthesizing and investigating a set of rationally designed educt molecules with the nitro group at various positions (Xie lab) we want to obtain a mechanistic understanding on how the nitro-to-amino conversion takes place. Finally, high-resolution SERS spectroscopy (Xie lab) in combination with accompanying DFT calculations (Schlücker lab) aims at resolving the corresponding reaction intermediates in a microfluidic reactor.