Low Temperature Water Gas Shift activity and durability of combustion synthesized Pt/CeO2-ZrO2 catalysts

Abstract: A highly dispersed Pt/CeO2 ZrO2 (3.8%wt Pt) water gas shift catalyst prepared by a single step solution combustion method has been shown to be superior to the corresponding catalyst prepared by the incipient wetness (IW) impregnation of platinum over the bare support Ce0.56Zr0.44O2 prepared via combustion route. The water gas shift (WGS) reaction has been studied between 453 and 633 K under a simulated standard reformate gas composition at a space velocity of 40,000 h-1. This catalyst with a surface area of 26 m2/g is found to be equally active when compared to an impregnated catalyst over a commercial support of comparable composition and higher surface area. Effects of pretreatments show the oxidized catalyst to be more active than the as-synthesized and hydrogen reduced catalysts. On the contrary, for the impregnated catalysts a reductive pretreatment gives the maximum activity. There is no significant methanation activity observed even at 600 K