简介

Electrochemistry and electrocatalysis We are concerned with the efficient generation and use of energy with a minimal environmental impact. Two classes of devices are very important in this regard: fuel cells and rechargeable batteries. Our research group studies the fundamental properties and behavior of electrodes employed in high-performance rechargeable batteries and fuel cells. We synthesize and characterize new electrode materials in order to gain a fundamental understanding of the relationships among atomic and electronic structure, electrochemical performance, and long-term stability. We investigate fundamental means of enhancing material utilization and stability through modifications in the composition and structure of the electrodes, thereby increasing cell specific energy and lifetime. The performance of electrodes employed in fuel cells that directly oxidize such fuels as methanol and ethanol is typically limited by slow electrochemical kinetics. The goals of our research performed on these electrodes are to synthesize new highly active electrocatalysts and characterize their kinetic and mechanistic behavior. By doing this, we identify electrocatalysts, electrode structures, and electrolyte compositions that lead to improved cell performance and lifetime. We rely heavily upon the use of advanced research tools, such as X-ray absorption spectroscopies (XAS) using synchrotron radiation (in collaboration with Prof. S. Cramer of UC Davis), to characterize the atomic and electronic properties of new electrode materials. Nuclear magnetic resonance spectroscopy (NMR) has been extended (in collaboration with Prof. J. Reimer of UCB) to the study of electronically conducting electrode materials. This powerful technique is used for the atomic-level study of electrode materials for both batteries and fuel cells. We have developed the capability of obtaining the NMR spectra in situ of carbon-containing adsorbates in submonolayer coverages on fuel cell electrocatalysts. We have also pioneered the use of photothermal deflection spectroscopy for the in situ characterization of electrochemical systems.