Stability of Supported Pd Nanoparticles During Exposure to Oxidizing and Reducing Environment

Phase stability of transition metal nanoparticles during exposure to elevated temperature and gaseous environment is a highly relevant topic in catalytic research with broad implications for rationalization of catalytic properties and design of new catalytic materials. For Pd based catalysts, the phase stability under oxidizing environment represents an important topic as many Pd based catalysts are used in various oxidation reaction. While the general features of Pd oxidation are rather well understood [1,2], the mechanism that controls the stability of Pd when prepared in the form of supported nanoparticles are still actively studied. For instance, the interaction of Pd with an oxide substrate can result in some intriguing properties, such as hysteresis of PdO dissociation/formation during heating/cooling cycles [3,4]. In Pd/Al2O3 system, the hysteresis is approximately 210°C, which is significantly higher than for other Pd-based catalysts supported on CeO2 and TiO2 with hysteresis as low as 45°C and 80°C, respectively.