Preparation Of Ce_xZr_1-xO₂Nano-support By Water-in-oil Microemulsion And NH₃System In Rotor-Stator Reactor

As environment pollution becomes more and more prominent, more attention has been paid to the protection of environment, and strict laws and standards for vehicle emissions will be implemented in China since July,2014. Three-ways catalyst (TWC) plays an important role in reducing the vehicle emissions, and the preparation of efficient and economical TWC has become a hot area of research in auto industry. CeO2has been widely used in TWC because it has a high oxygen storage capacity (OSC). The OSC of CeO2doped with Zr can be further improved. Therefore, nanoparticles of CeO2and CexZr1-xO2are ideal support materials for TWC.CeO2and Ce0.5Zr0.5O2nano-supports of catalyst were prepared by a reaction of water-in-oil microemulsion and NH3gas in a rotor-stator reactor (RSR) in this study. The influences of operating conditions were investigated and the optimum operating conditions were determined by BET, XRD, HRTEM analyses. CeO2nano-support with a diameter of5nm and specific surface area of104m2/g and Ce0.5Zr0.5O2nano-support with a diameter of5.5nm and specific surface area of215.6m2/g were obtained. These supports were doped with Au and evaluated for their catalytic activities by the CO oxidation reaction. Experimental results demonstrate that the nano-supports prepared by the microemulsion-gas method in the RSR had a small size and uniform size distribution, and exhibited high catalytic activity after doped with Au. CO was completely converted into CO2at a relatively low temperature by using the prepared catalysts.