Preparation method of bifunctional core-shell catalyst for preparing aviation kerosene through carbon dioxide hydrogenation

Abstract

The invention relates to preparation of a bifunctional core-shell catalyst for preparing aviation kerosene through carbon dioxide hydrogenation, and relates to preparation of core-shell catalysts. Thepreparation method comprises the four steps: synthesizing a Cu-Fe / SiO2 catalytic core, synthesizing a meso-TiO2@Cu-Fe / SiO2 core-shell catalyst, preparing a meso-TiO2 precursor solution, and preparingthe meso-TiO2@Cu-Fe / SiO2 core-shell catalyst. Through a core catalytic reaction, a shell layer reaction product CO is consumed in a catalytic system, and the reaction of the shell layer catalyst moves towards a positive reaction direction, so that the conversion rate of the shell layer catalyst is improved, and the overall conversion rate of the whole catalyst is further improved. The proportionof the active components Cu and Fe directly affects the length of the carbon chain of the product; an assistant regulates and controls the acid site strength of Cu-Fe / x-SiO2, the ratio of weak acid sites to strong acid sites and other factors, so as to enhance the selectivity of C8-C16 alkanes.

Description

Technical field: [0001] The invention relates to the technical field of preparation of core-shell catalysts, in particular to a preparation method of a dual-functional core-shell catalyst used for hydrogenation of carbon dioxide to produce aviation kerosene. Background technique: [0002] Aviation kerosene is used as fuel for aviation turbine engines, with suitable density, high calorific value, good combustion performance, less carbon deposition; good low-temperature fluidity, good thermal stability and anti-oxidation stability, high cleanliness, and little corrosion to machine parts It is suitable for gas turbine engines and ramjet engines, and is widely used in civil and military aviation vehicles. Different from other vehicles, due to the special requirements of the aviation engine on the energy density and weight of the fuel, the current aviation kerosene cannot be replaced by new energy power. Aviation kerosene is mainly composed of hydrocarbons with a carbon number o...

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Problems solved by technology

But TiO 2 At the same time, it has a small specific surface area (generally 2 / g), small pore volume and poor thermal stability (transition or structure collapse in the TPR process), thus limiting its use as Ni 2 P catalyst carrier

Li Dongyan et al. used thiophene as a model compound to investigate the effect of Ni loading and the Ni / P molar ratio of the precursor on the HDS performance of Ni2P / TiO2 catalysts. The results show that the increase of Ni loading makes the dispersion of active components on the carrier worse, and the Ni2P grains in the active center grow into Ni12P 5 phase, although the lower Ni loading has good dispersion, but the conversion of thiophene is still not high due to its small loading; while Ni2P / TiO2 catalyst increases first and then decreases with the increase of P content, because the grain size of Ni2P on the catalyst decreases when the initial P content increases appropriately, The dispersion of active components on the surface is high, and the catalyst has good desulfurization activity. Further increasing the initial P content will easily lead to excess P on the surface of the catalyst, a decrease in specific surface area, and a decrease in desulfurization activity.

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