Infrared and molecular beam studies of chemical reactions on solid surfaces

The experimental technology available to surface scientists has improved enormously over the last few decades, and most properties of solid surfaces can now be characterized in great detail. In particular, extensive knowledge has been accumulated on the structure, composition, and electronic and dynamic behaviour of many metal, semiconductor and ionic surfaces. Great progress has also been made in the use of those techniques to widen our understanding of surfaces physics, surface bonding and adsorption. The field of surface chemical kinetics, on the other hand, has been advanced to a lesser degree. Here we describe the approach taken in our laboratory to study the kinetics of the reactions followed by molecules adsorbed on solid surfaces, in particular those relevant to heterogeneous catalysis. Special emphasis is placed on describing the use of infrared spectroscopy for the characterization of surface intermediates and molecular beams for the measurement of reaction rates. Some examples of results from those studies are provided, and a few ideas for future directions in this field are proposed.