Ultrasmall Platinum Nanoparticles on Fe3O4: A Low-Temperature Catalyst for the Preferential Oxidation Reaction

Preferential oxidation (PROX) of CO in H-2-rich stream is critical to the production of clean H-2 for H-2-based fuel cells. A low-temperature fuel-cell start up is desirable for transportation applications. However, few catalysts are able to provide the required sustained activity at near-room-temperature conditions. The development of highly active and selective PROX catalysts is highly desirable but has been proven to be extremely challenging. Pt nanoparticles with a size of (1.2 +/- 0.1)nm were synthesized insitu on 32nm magnetite nanoparticles, which were previously deposited on alumina supports. The resulting catalyst was found to be highly active towards the preferential oxidation of CO in a H-2-rich reformate stream and gave 100% CO conversion at 25 degrees C with a weight hourly space velocity of 0.5mLmin(-1)mg(-1) and an oxygen excess factor (lambda) of 2.