Single-Complex, Single-Molecule, Single-Atom and Single-Site Studies of Chemical Events on Reactive Surfaces

反应表面化学事件的单络合物、单分子、单原子和单位点研究

• 批准号: RGPIN-2017-06483
• 负责人: McBreen, Peter
• 金额: $ 4.37万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=659149
• 关键词: Single; Complex; Molecule; Atom; Site

This research program is focused on the study of surfaces that are used to accelerate chemical processes. These surfaces are called heterogeneous catalysts. Their study is challenging area for several reasons. First, a surface is a two-dimensional system where almost all of the important chemical events occur only when the molecules make direct contact with the surface. As a result, the study of chemistry on surfaces requires very sensitive instruments. Second, chemical processes are often only accelerated at certain sites on the surface, so-called active sites. Third, if the surface binds any of the participants in the reaction sequence too strongly, it will clog up and the reaction will stop turning over. In this research program, we will primarily use scanning tunneling microscopy (STM) to study individual reactant molecules, or couples of molecules, at individual sites on precisely defined reactive surfaces. The STM technique can directly image conducting surfaces with atomic or sub-molecular resolution. There are three sub-projects: (1) A study of single-atom alloys (SAA), composed of atoms of a very reactive metal isolated on a relatively inert metal surface. These types of surfaces may achieve two objectives. They might limit the amount of precious metals needed to catalyze reactions. Also, they may prevent the surface from binding reactants or intermediates too strongly; (2) The study of enantioselective chemistry on surfaces. This in an area in which our group a currently doing leading work. During the last granting period (2011-2016), we carried out the definitive body of work on surface phenomena related to enantioselective hydrogenation on platinum. We are now proposing to move to the study of enantioselective CC coupling reactions on metal surfaces. Progress in this area, the synthesis of chiral products, is important for many reasons. Principally, the interaction of chemicals (for example, medicines) with our bodies depends sensitively on the chirality of the chemical. From the perspective of fundamental research in catalysis, the study provides remarkable insight on the use of weak intermolecular interactions to achieve reaction selectivity. (3) The study of two-dimensional metal carbides. We are experts in the surface study of conventional metal carbides. Recently, there has been an explosion of interest in the synthesis and application of 2D carbides. However, almost nothing is known about their surface chemistry-apart from the understanding that the surface termination has a profound affect on the material's properties. We are launching a systematic study of the surface chemistry of 2D carbides. HQP will directly perform all of the experimental surface science measurements in all of the projects. They will graduate with the skill of being completely at ease with complex instrumentation, and with fundamental expertise in the myriad applications of surfaces and interfaces.

该研究计划的重点是用于加速化学过程的表面的研究。这些表面称为异质催化剂。他们的研究是具有挑战性的领域，原因有几个。首先，表面是一个二维系统，仅当分子与表面直接接触时，几乎所有重要的化学事件都会发生。结果，表面上的化学研究需要非常敏感的仪器。其次，化学过程通常仅在表面的某些位置加速，即所谓的活跃位点。第三，如果表面在反应序列中结合了任何参与者，它将堵塞，反应将停止翻转。在该研究计划中，我们将主要使用扫描隧道显微镜（STM）在精确定义的反应表面上的单个位点研究单个反应物分子或分子的夫妻。 STM技术可以直接成像具有原子或亚分子分辨率的传导表面。有三个下注：（1）对单原子合金（SAA）的研究，该合金由在相对惰性金属表面上分离出非常反应性金属的原子组成。这些类型的表面可能实现两个目标。它们可能会限制催化反应所需的贵金属量。而且，它们可能会防止表面结合反应物或中间体过于强。 （2）对表面上的对映选择性化学的研究。这在我们的小组A当前从事领导工作的领域。在最后一个授予期（2011-2016）中，我们进行了与铂金上与对映射氢化有关的表面现象的确定作品。我们现在建议您研究金属表面上的对映选择性CC偶联反应。在这一领域的进展，手性产品的合成非常重要。主要是，化学物质（例如药物）与身体的相互作用敏感地取决于化学物质的手性。从催化中的基本研究的角度来看，该研究对使用弱分子间相互作用以实现反应选择性提供了显着的见解。 （3）研究二维金属碳化物。我们是常规金属碳化物表面研究的专家。最近，对2D碳化物的合成和应用引起了人们的兴趣。但是，从表面终止对材料的特性产生深远影响的情况下，他们的表面化学差别几乎一无所知。我们正在对2D碳化物的表面化学性质进行系统研究。 HQP将直接在所有项目中直接执行所有实验表面科学测量。他们将毕业，可以完全轻松使用复杂的仪器，并具有基本的专业知识，这些专业知识在众多的表面和界面应用中。