Liquid-solid and liquid-gas interfaces play a key role in numerous biological, chemical, and physical processes. Understanding the molecular environment and behavior in these systems is particularly challenging due to the few molecules involved. Vibrational sum-frequency generation (SFG) spectroscopy is a unique tool used to examine the structure and ultrafast dynamics of molecules at interfaces by capturing their vibrational motions. Additional information on the interfacial matrix can be obtained through more complex experiments- namely, the average molecular orientation can be determined via heterodyne detection, and inter and intramolecular coupling and spectral diffusion dynamics can be obtained by interferometric 2D SFG. This dissertation describes the development of these techniques and their application to a metal carbonyl based CO2 reduction catalyst on nanocrystalline and single crystal TiO2 to study the impact that immobilization has on the molecular structure and vibrational properties which influence the catalytic process.