Morphology and size effect of ceria on methanol oxidation in non-thermal plasma

The morphology effect and size effect of Ceria (CeO2) on methanol oxidation in non-thermal plasma (NTP) system were investigated. CeO2-Rod and CeO2-Cube with individual three sizes were synthesized and presented strong morphology-dependent and size-dependent activity, namely, CeO2-rod catalyst exhibited superior performance than CeO2-Cube, while each of them showed improved catalytic activity as the size reduced. Various characteristic methods showed that CeO2-Rod in smaller size possesses more surface adsorbed oxygen species than CeO2-Cube. Further experiments confirmed that the dependence of catalytic activity on CeO2 morphologies and CeO2 sizes was derived from their ozone utilization. To further investigate the difference of surface reaction pathways between the catalysts, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments were conducted and the results showed that the methanol adsorption behavior and oxidation process on catalyst surface differ in CeO2 morphologies.