SO2-Poisoning-Resistant CeO2@TiO2 Nanorod with the core–shell Structure for the Catalytic Oxidation of CO

The core–shell-structured CeO2@TiO2 nanorods and traditional CeTiOx nanoparticles were prepared to study the role of the core–shell structure in CO catalytic oxidation and SO2 resistance. CeO2@TiO2 maintained a higher than 98% CO conversion at 300 °C in the flue gas containing 1000 ppm CO and achieved about 68% CO conversion after adding 500 ppm SO2 for 5 h. The core–shell structure mitigated the crystallinity loss of the CeO2 core and pore blockage of CeO2@TiO2. TiO2 avoided the reaction between SO2 and CeO2 to protect CeO2 from SO2 poisoning. In the case of SO2 passing through the shell, TiO2 could inhibit the formation of Ce2 (SO4)3, delaying the deactivation of the CeO2 core. Furthermore, the sulfate deposited on CeO2@TiO2 possessed a smaller amount and poorer thermal stability than that on CeTiOx. The design of the core–shell structure provides an effective route to enhance the SO2-poisoning resistance of catalysts in CO oxidation.