Operando Studies of Palladium-Catalysed Cross-Coupling Surface Chemistry

钯催化的交叉偶联反应是学术界和工业界采用的关键技术，然而精细化工领域迫切需要新的催化系统来进行大规模、连续的加工。这一建议支持开发替代的、多相Pd催化的工艺来满足这一需求。这种催化清洁技术的商业化还有待对其最佳配方和相关反应条件的详细了解。这些信息反过来需要深入了解这种表面反应的机制及其相关的失活途径，以便控制活性和选择性(同向偶联与交叉偶联)。在这里，我们建议通过使用表面光谱和机理反应探针在定义良好的模型钯表面上获得Heck和Suzuki-Miyaura化学的微观水平的理解。我们最近率先将原位X射线光电子能谱应用于具有工业意义的表面催化过程的实时研究，包括炔烃三聚、C-H活化和VOC破坏。这些方法还将使我们能够确定多相催化的交叉偶联是否与其更传统的均相对应物共享共同的反应中间体和限速步骤。该项目的智力成果将对设计高性能分散型钯催化剂的新工具箱起到无价的作用，这将给有机合成化学带来革命性的变化。

Pd-catalysed cross-coupling reactions represent key technologies employed within academia and industry, however the fine chemicals sector urgently needs new catalytic systems for large-scale, continuous processing. This proposal underpins the development of alternative, heterogeneous Pd-catalysed processes to meet this demand. Commercialization of such catalytic clean technologies awaits detailed knowledge of their optimal formulation and associated reaction conditions. This information in turn requires insight into both the mechanisms of such surface reactions and their associated deactivation pathways in order to control both activity and selectivity (homo- versus cross-coupling). Here we propose to obtain microscopic-level understanding of Heck and Suzuki-Miyaura chemistry over well-defined model palladium surfaces through the use of operando surface spectroscopies and mechanistic reaction probes. We have recently pioneered the application of in-situ, X-ray photoelectron spectroscopy for real-time investigations of industrially significant, surface catalysed processes including alkyne trimerisation, C-H activation and VOC destruction. These methodologies will also allow us to determine whether heterogeneously catalysed cross-coupling shares common reaction intermediates and rate-limiting steps with its more conventional homogeneous counterparts. The intellectual output from this project will be invaluable in designing a new toolbox of high performance dispersed Pd catalysts that will revolutionise organic synthetic chemistry.