Copper and nickel catalysts supported on praseodymium-doped ceria (PDC) for the water-gas shift reaction

Abstract

The aim of this work is to study the behavior of Cu and Ni catalysts supported on praseodymium-doped ceria (PDC) for the WGS reaction. Samples were prepared by impregnation of several PDC supports (praseodymium content in the range 0–50 wt%) synthesized by the urea thermal decomposition method. Bare support and catalysts were characterized by BET, XRD, oxygen storage capacity and TPR. The activity tests were carried out in an atmospheric fixed bed reactor, using a CO/H2O/H2/N2 mixture as the feed stream. Doping of ceria with small loading of Pr increases the surface reducibility and the oxygen storage capacity of ceria. Nickel catalysts are more active than copper ones. In both cases, catalysts supported on PDC with 5 Pr wt% are more active than samples supported on pure ceria. Methanation, which is likely to occur on Ni catalysts, is moderated in samples supported on praseodymium-doped ceria.