Base-Accelerated Degradation of Nanosized Platinum Electrocatalysts

In the pursuit of a hydrogen economy, extensive research has been directed at developing acidic and alkaline fuel cells. Such cells often utilize platinum-based catalysts. These materials have studied extensively in conditions but not ones. This focus on systems creates marked knowledge gap, since recent studies indicate that carbon-supported platinum (Pt/C) electrocatalysts degrade more rapidly bases than acids. Addressing this present work investigates Pt/C degradation pH 2 12 using electrochemistry, transmission electron microscopy (TEM), situ X-ray absorption spectroscopy (XAS). TEM XAS reveal accelerated high levels, which results increased Ostwald ripening, Smoluchowski agglomeration, nanoparticle detachment. processes are driven by platinum-catalyzed carbon corrosion dissolution redeposition nanoparticles. Although these take place both low basic accelerate degradation. Base-enhanced Pt was assessed further detail, revealing an oxidation onset reduction 100 mV base; however, there were no significant differences between undissolved acid base. The suggest soluble products stabilized base instead. conclusions important for translating acid-based literature to conditions.