Support dependence of MeOH decomposition over size-selected Pt nanoparticles

We present here the decomposition of methanol over Pt nanoparticles supported on a series of oxide powders. The samples tested may be roughly grouped in two categories consisting of large (similar to 15-18 nm) and small (similar to 8-9 nm) Pt particles deposited on reducible (CeO2, TiO2) and non-reducible (SiO2, ZrO2, Al2O3) supports. The smallest particles (similar to 8 nm), deposited on ZrO2, were found to be cationic and the most active for the decomposition of methanol. Furthermore, the stability of metallic Pt and its oxides was observed to be dependent on the choice of support. In all Pt containing samples the reaction proceeds via he direct decomposition of methanol, as no significant amounts of by-products were detected in the experimental range of 100-300 degrees C.