Integrated Theoretical and Experimental Studies of Fuel Cell Electrocatalysts

37 S ignificant progress has taken place over the past decade or so in understanding catalysis in electrochemical systems. Electrocatalysts used in fuel cells are a long-standing example of the application of nanotechnology in electrochemistry. In electrocatalysis in proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs), the relatively low operating temperature and the use of reformed fuels or methanol put a premium on highly active, high surface area electrocatalysts. The efforts of the past decade did not represent a complete departure from previous work. There was a substantial base of work that defined many critical aspects of the field. However, new tools are available that enable us to look in more detail at more complex interfaces than ever before. This includes firstprinciples quantum mechanical methods that begin to provide reliable descriptions of elementary processes occurring in complex environments such as the surface of real-world fuel cell catalysts. Stochastic and dynamic simulations are available that can follow the kinetic and temporal behavior of these systems. For the past several years, the authors have collaborated in a U.S. Army Research Office-sponsored MultiUniversity Research Initiative (MURI) entitled, “Integrated Computational and Experimental Studies of Fuel Cell Electrocatalysts.” We have focused on the development, refinement, and application of theoretical tools and experimental methods to interrogate the fundamental processes that control fuel cell systems. A theoretical framework for the robust description of electrode processes is also being developed. Experimental work is a critical adjunct to the theory, providing the validation as well as additional, targeted insight into features arising from the theory. We are gathering theory and experiment into a “toolkit” and this article provides a snapshot of the status of this effort. Integrated Theoretical and Experimental Studies of Fuel Cell Electrocatalysts