The overarching scientific objective of this program is to enhance the understanding of hydrogen economy critical phenomena through a surface stress paradigm. This BES program is the first time that surface stress measurements have been used to look at critical phenomena such as oxygen reduction, catalyst poisoning, and H-storage. In this context, surface stress measurements have proven to be a powerful spectroscopic tool for studying catalysts and hydrogen storage materials in both vacuum and electrochemical environments. In each of these cases we have been able to determine thermodynamic, kinetic, and structural aspects of the phenomena under study.