Ce0.5Zr0.4Sn0.1O2/Al2O3catalysts with enhanced oxygen storage capacity and high CO oxidation activity

Abstract

Ce_0.5Zr_0.4Sn_0.1O₂/Al₂O₃ catalysts were prepared by a coprecipitation route using Ce(NH₄)₂(NO₃)₆, Zr(NO₃)₃·2H₂O, SnCl₄·5H₂O and Al₂O₃ as the starting materials, and were evaluated as a promoter in automotive catalysis by X-ray diffraction, transmission electron microscopy and the Brunauer–Emmet–Teller (BET) technique. The oxygen storage capacity (OSC) values of the samples were measured using thermogravimetric-differential thermal analysis at 600 °C with a continuous flow of CO–N₂ gas and air alternately. The CO oxidation activity of the synthesized sample was evaluated via a gas FTIR spectrometer for analysis of gas compositions. The Ce_0.5Zr_0.4Sn_0.1O₂/γ-Al₂O₃ composite possessed excellent thermal stability, enhanced OSC values, and high CO oxidation activity at the low temperatures even after calcination at 1000 °C for 20 h.