Catalytic Activity of Tandem Catalysts in CO2 Hydrogenation to Olefins Depending on Component Arrangement

Abstract

A series of tandem catalysts based on indium, zinc, and gallium oxides were synthesized, with a CHA-type silicoaluminophosphate and an MFI-type zeolite as acidic components. These catalysts were tested in the conversion of carbon dioxide to olefins at 380°C and 27 bar, with the component arrangement being varied. The physicochemical properties of the catalysts and their components were characterized by low-temperature nitrogen adsorption, X-ray diffraction analysis (XRD), X-ray fluorescence spectrometry (XRF), scanning electron microscopy (SEM), and temperature-programmed desorption of ammonia (NH₃-TPD). It is shown that the optimal arrangement of the hydrogenating and acidic components in the reactor depends on the type of the hydrogenating component. The best catalytic performance (33% CO₂ conversion and 5.6% yield of hydrocarbons) was achieved in the presence of a ZnGa₂O₄/MFI catalyst with the components being mechanically mixed.