An ab initio path integral treatment of hydrogenation reactions at metal surfaces

涉及金属表面氢原子的键的形成和断裂是多相催化的基础。例如，通过氢分子中H-H键的断裂形成水，随后原子氧和羟基的氢化反应产生水。量子核效应--如隧道效应和量子离域效应--在决定这些过程的机制和速率方面所起的作用在很大程度上仍未得到探索。这是事实，尽管人们知道氢的量子核效应在室温及以下可能是显着的，尽管经济和环境需求日益增长，以更好地了解和利用越来越低的温度下的催化作用。在这里，我们计划用最先进的第一原理电子结构方法来解决这种情况。具体来说，将开发和应用从头算路径积分技术，严格探索量子核效应在元素扩散过程和涉及金属表面氢的反应事件中所起的作用，最终实现对铂上的成水反应的全量子从头算处理。这是一个非常冒险但可行的项目。这里提出的方法论发展需要一名博士后参与，这是项目三年生命周期所要求的。同样，这个项目将严重依赖英国的下一代兆兆级高性能计算设施(Hector)，事实上，直到现在Hector即将安装，这个对计算要求很高的项目才在英国变得可行。

The making and breaking of bonds involving hydrogen atoms at metal surfaces is the bread and butter of heterogeneous catalysis. Water formation from its elements, for example, proceeds through the cleavage of the H-H bond in the H2 molecule followed by subsequent hydrogenation reactions of atomic oxygen and hydroxyl to yield water. The role quantum nuclear effects - such as tunnelling and quantum delocalization - play in determining the mechanisms and rates of these processes remains largely unexplored. This is true despite knowledge that the quantum nuclear effects of hydrogen can be significant at room temperature and below and despite the growing economic and environmental needs to better understand and exploit catalysis at increasingly low temperatures. Here we plan to make a start at addressing this situation with state-of-the-art first principles electronic structure approaches. Specifically ab initio path integral techniques will be developed and applied to rigorously explore the role quantum nuclear effects play in elementary diffusion processes and reaction events involving hydrogen at metal surfaces, culminating in the fully quantum ab initio treatment of the water formation reaction on Pt. This is a highly adventurous yet feasible project. The methodological developments proposed here require the involvement of a post-doc, which is requested for the three year lifetime of the project. Likewise this project will rely heavily on the UK's next generation terascale high performance computing facility (HECToR), and, indeed, only now with the imminent installation of HECToR does this highly computationally demanding project become feasible in the UK.