Molecular scale reactivity at bimetallic surfaces: bridging the pressure gap

双金属催化剂广泛用于几种催化过程，例如不饱和分子的氢化或氧化反应。与相关的纯金属相比，这些合金催化剂显示出改善的选择性和活性或对毒物的更高稳定性。已经在UHV或低压条件下进行了对良好限定的单晶表面的研究，但是对于它们在催化反应的真实的压力和温度条件下的有益效果的原因仍然很少有基本的理解。这个建议的目的是建立一个密切的相互作用的实验技术和理论计算的分子反应过程中，在定义良好的表面在超高真空条件下，在高压下的详细的严格和定量的了解。波恩小组将贡献其在合金表面超高真空技术方面的广泛经验。格勒诺布尔集团将提供其最先进的高压表面技术（ESRF的X射线衍射和实验室SFG装置）。此外，维勒乌尔巴讷团队一方面将带来其在催化原位表征（STM，PM-IRRAS，模型反应性）方面的强大专业知识，另一方面将带来其在催化应用量子化学计算方面的知识。其目的是创造一个独特的结构技术组合（在UHV：STM和LEED，在高压：STM和X射线衍射），振动方法（在UHV：STS和HREELS，在高压：IR和SFG），催化模型表面和量子计算（包括气体压力的影响）。广泛结合的方法，结构，振动和化学信息，无论是在超高真空和现实的压力，应导致详细的基本了解合金表面的不饱和分子的表面化学。在化学工业或能源生产中具有重要应用的目标反应将是不饱和醛的选择性氢化和氢气中痕量CO的选择性氧化。这种广泛的实验和理论方法只能在这种合作的框架内进行。

Bimetallic catalysts are widely used for several catalytic processes such as the hydrogenation of unsaturated molecules, or oxidation reactions. These alloy catalysts show an improved selectivity and activity or a higher stability against poisons when compared to the related pure metals. Studies on well defined single crystal surfaces have been performed in UHV or low pressure conditions but there is still little fundamental understanding of the reasons for their beneficial effect under the real pressure and temperature conditions of the catalytic reaction. The purpose of this proposal is to establish a close interaction between experimental techniques and theoretical calculations for a detailed rigorous and quantitative understanding of molecular reaction processes at well defined bimetallic surfaces both under UHV conditions and under high pressure. The group of Bonn will contribute its broad experience in UHV techniques on alloy surfaces. The group of Grenoble will provide its state of the art surface techniques at high pressure (X-ray diffraction at ESRF and laboratory SFG set-up). Moreover, the group of Villeurbanne will bring on one hand its strong expertise in in-situ characterization of catalysis (STM, PM-IRRAS, model reactivity) and on the other hand its knowledge in quantum chemical calculations applied to catalysis. The aim is to create a unique combination of structural techniques (in UHV: STM and LEED, at high pressure: STM and X-ray diffraction), vibrational methods (in UHV: STS and HREELS, at high pressure: IR and SFG), catalysis on model surfaces and quantum calculations (including the influence of gas pressure). The wide combination of approaches, with structural, vibrational, and chemical information, both in UHV and at realistic pressure, should lead to a detailed fundamental understanding of the surface chemistry of unsaturated molecules at alloy surfaces. The target reactions, which have important applications in the chemical industry or for energy production, will be the selective hydrogenation of unsaturated aldehydes and the selective oxidation of CO traces in hydrogen. Such a broad experimental and theoretical approach can only be undertaken in the framework of this collaboration.