Effect of precursors on graphene supported platinum monometalic catalysts for hydrothermal gasification of biomass compounds to hydrogen

In the present study, H₂PtCl₆, PtBr₂, PtCl₂ and PtI₂ precursors were evaluated for developing graphene supported platinum catalysts to be used for hydrothermal gasification of biomass compounds to hydrogen. The catalysts were prepared by impregnation and ultrasound-assisted wet impregnation methods. Hydrogen production activity of the catalysts were determined by aqueous-phase reforming (APR) as a low temperature hydrothermal gasification technology. Glucose, a simple biomass-derived compound, was used as substrate in APR process. The size and distribution of Pt particles on the graphene were highly dependent on the precursors used in the preparation process. Targeted metal loading (8 wt%) with smaller size and better dispersion of metal particles on the support was achieved with ultrasound-assisted method. PtCl₂ was found to be best precursor to deposit Pt particles on graphene with relatively small and uniform with narrow dispersion. The catalysts prepared by ultrasound-assisted method using with different precursors produced similar amounts of hydrogen.