Influence of synthetic parameters and reaction conditions on properties of CexZr1-xO2 for CO preferential oxidation reaction in H2-rich gases

CexZr1-xO2 (x= 0-1) catalysts were prepared by urea grind combustion method (UGC) and tested for CO preferential oxidation in H-2-rich gases. The catalytic performances of CexZr1-xO2-UGC-400 are comparable to CexZr1-xO2-SG-400 and higher than CexZr1-xO2-SA-400. The optimal Ce/Zr molar ratio, calcination temperature and urea addition (R value) for synthesizing CexZr1-xO2 catalysts are Ce/Zr = 4: 1, 300 degrees C and R = 1.0, respectively. Ce0.8Zr0.2O2 catalyst prepared with this route can well adapt the change of gas hourly space velocity (GHSV), and no any obvious change is observed both in CO conversion and O-2 selectivity with GHSV increasing from 12000 to 48000 h(-1). Both CO conversion and O-2 selectivity of Ce0.8Zr0.2O2 maintains relative stability during 72 h time-on-stream test. (C) 2015 Published by Elsevier Ltd.