The transition state in catalytic surface chemistry

The transition states for the elementary steps of a catalytic surface reaction mechanism determine the overall rates of catalytic processes. Unfortunately, our understanding of the nature of transition states on surfaces remains very poor due to the extreme difficulties associated with experimental and computational methods for probing such metastable species. Currently progress is being made along three fronts: state-resolved molecular adsorption and desorption experiments, measurements of substituent effects on reaction barriers, and the use of computational simulation.