This Career Advancement Award (CAA) to Professor Grassian is for the investigation of fundamental photochemical reactions of molecules adsorbed on single-crystal metal surfaces. Pulsed laser, time-of-flight (TOF) mass spectrometry and infrared spectrophotometry will be used to analyze the products from photodecomposition and photodesorption reactions occuring on the surface of metal particles. In addition, the TOF instrumentation will allow the measurement of the angular and translational energy distributions of the proposed photooxidation and photohydrogenation reactions. The goal is to improve our understanding of photo-induced chemical reactions which occur on the surface of metal catalysts. %%% Career Advancement Awards allow female investigators to initiate research programs in new or innovative areas of investigation. Professor Grassian will use this CAA to expand her research into the area of photochemistry on the surface of single-crystal metal particles. The results will provide increased knowledge concerning photo-induced chemical reactions observed on catalytic surfaces.