Theoretical analysis of electrochemical surface-area loss in supported nanoparticle catalysts.

In polymer electrolyte fuel cells a decrease in catalytic surface-area within the cathode catalyst layer is a critical barrier to commercialization. This loss in catalytic surface-area manifests as a loss in cell voltage and thus power density of the cell. It has been established that potential cycling accelerates the loss in catalytic surface-area yet isolating the contributing mechanisms as well as relating mechanisms to operating conditions is not as straightforward.

Nonmonotonic dynamics in Lifshitz-Slyozov-Wagner theory: Ostwald ripening in nanoparticle catalysts.

Nanoparticle catalysts dispersed on high-surface-area electronic support materials are used in a wide range of applications. Nano-sized particles afford a high active surface area per unit volume of an electrocatalytic medium. However, the gain in active surface area for desired surface reactions is offset in part by enhanced rates of degradation processes that cause losses in catalyst mass, catalyst surface area, and electrocatalytic activity.