The objectives of his program are pursued through a combination of experimental and theoretical methods. Spectroscopic techniques, including IR, Raman, NMR, UV-Visible, XANES, and EXAFS, are used to characterize catalyst structure and adsorbed species under actual conditions of catalysis. Isotopic tracers and temperature-programmed adsorption and reaction techniques are used to elucidate the pathways via which catalyzed reactions occur. Quantum chemical calculations are conducted to define the structure and energetic of adsorbed species and the pathways by which such species are transformed. The combined use of theory and experimental methods enables the attainment of a deeper understanding of the core issues of interest than can be achieved by the use of either approach alone. In pursuing his research, Professor Bell draws upon 40 years of experience in the pursuit of fundamental issues relevant to catalysis. He is the author or co-author of over 550 technical publications.