Probing Site Activity of Monodisperse Pt Nanoparticle Catalysts Using Steam Reforming of Methane

Monodisperse platinum nanoparticles between 2 and 8 nanometers were synthesized to help quantitatively investigate the size dependency and the activity of surface sites for steam reforming of methane reaction to produce hydrogen gas. It was observed that these monodisperse nanoparticles aggregated to almost double the size of nanoparticles after a few hours of steam reforming reactions at high temperatures. Using the size of nanoparticles determined by transmission electron microscopy and the measured turnover frequencies for these monodisperse nanoparticles, it was found, for the first time, that the activity of these nanoparticles of different sizes for steam reforming of methane can be described mathematically using only two variables of the type and the coordination number of the surface atoms.