Title : Efficient CO2 hydrogenation to straight chain olefins over simple and robust alkali promoted Fe catalysts
Abstract:
Use of carbon dioxide for the production of fuels and chemicals, which is widely emitted from fossil fuels on earth atmosphere and responsible for the greenhouse gas effect. Currently, utilization of carbon dioxide (CO2) to various chemicals using homogeneous, heterogeneous, photo or electro-catalysts considered great importance both in industry and academics. As can be seen from the literature, there are many successful examples of commercial use of CO2 to chemicals; for example use of CO2 as feedstock in syn-gas for the production of methanol and dimethyl ether. Further investigation under consideration to develop active and selective catalysts for hydrogenation of CO2 to synthetic fuels, light olefins, ketones, aldehydes and higher alcohols. The recent scenario on catalytic conversion of CO2 to value-added chemicals and fuels has been considering as a very important objective, especially CO2 hydrogenation for the production of lower olefins is highly important and challenging. Here, we develop efficient catalyst with single step preparation procedure, easy reducibility to metallic iron along with in-situ formation of active iron carbide species via methane activation at 750 °C for ‘x’ min (x=10 and 25 min) in a fluidized bed reactor, which are considered to be key steps for efficient activity and selectivity for FT process. Methane activation acts as a source of hydrogen, which is required for reduction iron oxide to metallic Iron. Here, our catalytic approach suggests that the efficient catalytic hydrogenation of carbon dioxide at temperature 250 °C with very high selectivity to olefins. At the same time, carbon source in terms multiwall CNTs obtained from the carbon of methane, which is key role for the formation iron carbide phases. Alkali promoted iron carbide catalyst possess efficient conversion of CO2 about 28% with combined selectivity to light olefin (C2-C4), higher chain olefins (C5-C9) is about <55%.
