Flame spray pyrolysis synthesized CuO–CeO2 composite for catalytic combustion of C3H6

Abstract

C3H6 is a typical volatile organic compound (VOC) which is greatly harmful to the environment, however, it is difficult to achieve a complete C3H6 removal at low temperature via the catalytic combustion treatment. In this study, high-performance catalysts of CuOCeO2 composites were synthesized via a modified flame spray pyrolysis (FSP) method for the catalytic combustion of C3H6. The CuOCeO2 composites with different Cu molar ratios of 10, 25, 35, 50, and 75% were characterized by N2 sorption-desorption analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), H2 temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). Results show that the composites preserve a nanometer-sized structure with stable micromorphology, which is hardly affected by the molar ratio of Cu. The FSP method is confirmed to be capable of producing solid solution oxides in the composites, which provide abundant reactive oxygen species and good reducibility. XPS, H2-TPR results indicate that Cu loading content has a significant impact on the catalytic properties of the prepared CuOCeO2 catalysts by influencing the content of the solid solution. Compared with other methods, the optimized FSP method can significantly improve the loading of Cu without producing large crystalline CuO particles on the catalyst surface. C3H6 conversion reached a 90% conversion at 380 °C indicating an outstanding catalytic performance of the FSP-synthesized CuOCeO2 catalysts with 35 mol% Cu loading. Moreover, the ignitability of C3H6 is also affected by the catalyst's physicochemical properties, and different active species play the main role in different temperature intervals.