Our electrocatalyst research activities focus on the development of catalytic materials for proton exchange membrane (PEM) fuel cells and PEM water electrolyzers.  Some of these activities include the development of industrially relevant synthesis routes for the preparation of highly active and stable oxygen reduction reaction (ORR) catalysts for PEM fuel cells (PEMFCs) based on carbon-supported PtxY-alloy nanoparticles. Our group has also developed one of the most active bimetallic core-shell catalysts for the hydrogen oxidation reaction (HOR) for application in PEMFC anodes, composed of nanometer-sized ruthenium particles covered by several monolayers of platinum.  In order to mitigate the corrosion of the carbon supports used for cathode catalysts during transient operation of PEMFCs, selective Pt/TiOx catalysts are developed that are active for the HOR and extremely poor for the ORR.