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

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.