Synthesis of light olefins from CO2 hydrogenation over (CuO-ZnO)-kaolin/SAPO-34 molecular sieves

Cu-Zn oxide/SAPO-34 molecular sieves was used as bifunctional catalyst for the direct synthesis of light olefins from CO2 and H-2, but the production of SAPO-34 molecular sieves required high cost and the Cu-Zn oxide (CuO-ZnO) particles were prone to sintering, which severely restricted its industrial application. Herein, kaolin was used as raw material to prepare SAPO-34 molecular sieves and as supports to prepare kaolin-supported CuO-ZnO catalysts. The samples were characterized by X-ray diffraction, Scanning Electron Microscope, Energy Dispersive Spectroscopy, N-2 sorption, H-2 temperature programmed reduction, NH3 temperature programmed desorption and Fourier Transforms Infrared spectra techniques. The results showed that the SAPO-34 molecular sieves presented lamellar structure and the CuO-ZnO particles were well dispersed on the surface of kaolin. The results of catalytic reaction for the direct synthesis of light olefins from CO2 and H-2 indicated that the (CuO-ZnO)kaolin/SAPO-34 molecular sieves could enhance not only the yield of light olefins, but also the lifetime.