Monday, November 8, 2010: 9:12 AM
254 C Room (Salt Palace Convention Center)
One of the promising outcomes from studies of oxygen reduction electrocatalysts in polymer exchange membrane fuel cells is the structural concept of core-shell electrocatalyst. The core-shell electrocatalyst is based on the combination of a not expensive core, which can favourably modify the electronic and geometric properties of the surface, supporting a platinum shell that bare good catalytic properties. However, some problems remain: the accompanying core metals that segregate toward the surface are prone to easy dissolution in acid medium. We have proposed a new catalyst structural concept for preventing metal dissolution in acid medium; it consists of shell-anchor-core structure. The anchor region prevents core metal alloy atoms segregation toward the surface, and anchors the shell to the core preventing metal dissolution in acid medium. Based on Density functional theory (DFT) studies, we propose and test the activity and stability properties of a new material containing an anchor comprising a thin film of a transition metal and a small-radius species located in the film's interstitial sites.