An experimental study on Pt-based bimetallic oxidative steam reforming (OSR) catalysts

Abstract

In the current study, Pt-Ni/Al2O3 system was optimized for catalytic hydrogen production via oxidative steam reforming of propane. Oxidative steam reforming of propane was tested over four Pt-Ni/d-Al2O3 bimetallic and one Pt-Au-Ni/d-Al2O3 trimetallic catalysts aiming to investigate the effect of Ni:Pt loading ratio on catalyst performance. Catalyst types and reaction conditions were firstly arranged to identify the effect of reaction temperature, carbon to oxygen ratio, residence time, and catalyst loadings on hydrogen production. The catalysts were prepared as having two different levels of Pt loadings (0.2 wt % and 0.3 wt %) and two different levels of Ni loadings (10 wt % and 15 wt %) on alumina support. Gold was added to the Pt-Ni system, aiming to see its affect both on OSR performance of the catalyst as well as its secondary WGS activity. The effect of C/O2 ratio on the hydrogen production and H2/CO selectivity were found dependent on the Pt and Ni loadings, and their loading ratio (Ni:Pt) as well. The highest hydrogen production and H2/CO ratio levels were obtained for the highest C/O2 ratio tested. Lower Pt loadings have made the catalysts more sensitive to the changes in C/O2 ratio. An optimum Ni:Pt ratio was found around 50 by weight due to suppressed methanation and enhanced hydrogen production activities of these catalysts. The presence of gold in the trimetallic catalyst caused poor activity and selectivity in comparison to bimetallic catalysts.