Abstract
This study investigated the influence of dopants (Gd, Nb, Pr, and Zr) on the performance of Pt/CexMe1-xO2-γ/Al2O3 catalysts for the methane steam reforming (SRM) at 1073 K and at different space velocities. In-situ XRD, in-situ XANES, and Raman spectroscopy revealed the formation of a solid solution on the supports with Gd, Pr and Zr and an improvement in reducibility. No evidence of complete niobium inclusion into the ceria framework was observed and AlNbO4 and CeNbO4 phases were detected. All catalysts exhibited a severe initial deactivation, however, with Pt/CeNb/Al being most stable. Analyses of all spent catalysts revealed a negligible carbon deposition during the catalytic tests. TEM, XRD and N2 physisorption showed a collapse of the alumina structure and sintering of Pt particles as causing the early deactivation. The formation of segregated phases for Nb-doped ceria improved the thermal resistance of alumina and provided a closer contact with Pt crystallites, resulting in better stability.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
