Novel catalyst for the WGS reaction in a Pd-membrane reactor

Abstract

A Pt/La2O3·SiO2catalyst was synthesized and tested in the WGS reaction. Kinetic measurements werecarried out in a conventional fixed-bed reactor operated in differential mode while the stability test wasconducted in integral regime. The fresh and used catalysts were characterized through XRD, XPS, Ramanspectroscopy and H2chemisorption. The Pt(0.6 wt%)/La2O3(27 wt%)·SiO2catalyst showed high activityand WGS selectivity, no carbon formation and high stability. After use no changes were observed in thePt dispersion. The catalyst was also tested in a tubular Pd-Ag membrane reactor in order to gauge theperformance of this device using CO conversion, hydrogen recovery and H2production as parameters. Themembrane reactor experiments were performed between 673 and 723 K and at pressures ranging from100 kPa to 800 kPa. The low methanation activity was monitored in all cases. Under the best operatingconditions, a CO conversion of 98% and a hydrogen recovery of 90% were reached operating at 800 kPa inthe retentate side, and at 100 kPa in the permeate side.