Catalytic Conversion of CO2 to Fuel and Fine Chemicals over Octahedral Molecular Sieve Manganese Oxide Supported Catalysts

摘要

CO2 conversion to useful hydrocarbons via the Fisher-Tropsch (F-T) synthesis has been of interest due to simultaneous increase of product value and reduction of CO2 emissions. A few previous studies have been reported in CO2 hydrogenation, and the main challenge is high methane formation and less valued products. For a practical industrial application of CO2 hydrogenation, more high valued products are demanded to compensate the costly input of hydrogen and energy. Liquid fuel, C2-C6 carboxylic acids, and α-hydroxyl acids have been synthesized with high selectivity in CO2 hydrogenation using cryptomelane-type octahedral molecule sieve manganese oxide (K-OMS-2) supported Fe and Co catalysts. K-OMS-2 supports are composed of 2 X 2 edge-shared MnO6-octahedral chains, which are corner shared to form one-dimensional tunnels (4.6 x 4.6 A). K-OMS-2 supports used in these studies are nano-fibers with a diameter of 20-100 nm and a length of 2-50 μm. K-OMS-2 supports provide K+ ions as promoters. The K-OMS-2 supported Fe catalysts are iron framework doped Fe-K-OMS-2. The K-OMS-2 supported Co catalysts are prepared by an incipient wetness impregnation (IWI) method.