(77a) Climbing Elementary Steps to the Pinnacle: Surface Science to Heterogeneous Catalysis

Madix, R. J. - Presenter, Harvard University
For decades our goal has been to make studies of reactivity on well-defined single crystal surfaces relevant to the development of heterogeneous catalysts in much the same spirit as gas phase kinetics and mechanism are important to understanding atmospheric chemistry. As long ago as the mid 1970’s significant progress was made in the understanding of partial oxidation of methanol over silver catalysts based on model studies resulting from the graduate work of Prof. Wachs, which were supported years later by DFT-based microkinetic modeling. Recently, based on mechanistic studies in ultrahigh vacuum, metallic gold has emerged as a promising catalyst for selective oxygen-assisted coupling reactions of alcohols and amines to yield industrially important classes of molecules, including esters and amides. The fundamental mechanistic principles determined from the model systems stem directly from the body of work on silver single crystals, but extend well beyond. Consequently, these principles have been used to predict new reactive pathways for other more complex molecular transformations under practical catalytic conditions. Studies ranging from those on single crystal gold to continuum flow and pulse reactors will be discussed. These fundamental reaction paradigms will be extended to the understanding of oxygen-assisted coupling mechanisms on metallic alloy gold catalysts of varying nature across a broad range of studies, including gas phase and liquid phase systems.