Vanadium-doped silica-based mesoporous molecular sieve catalyst and its preparation method and application

Abstract

The invention provides a vanadium-doped silicon oxide-based mesoporous molecular sieve catalyst, as well as a preparation method and application thereof. According to the catalyst, a pure silicon mesoporous molecular sieve KIT-6 is taken as a carrier, vanadium oxide is taken as an active ingredient, and is doped into a framework of the pure silicon mesoporous molecular sieve KIT-6, and the molar ratio of V to Si is 0.1:100 to 8:100. The invention further provides the preparation method for the catalyst and the application of the catalyst to selective oxidative dehydrogenation of propane for production of olefin. According to the vanadium-doped silicon oxide-based mesoporous molecular sieve catalyst, the dispersity of the active ingredient vanadium is higher, the concentration of an active site is higher, and the stability of the active site is higher, so that the catalytic activity of the catalyst is higher. When the catalyst is applied to reaction of selective oxidative dehydrogenation of the propane for production of the olefin, the molar recovery rates of products propene and olefin of selective oxidation reaction of the propane can reach 35.6 percent and 38.6 percent respectively.

Description

technical field [0001] The invention relates to a vanadium-doped silica-based mesoporous molecular sieve catalyst, a preparation method and application thereof, and belongs to the technical field of petrochemical catalysis. Background technique [0002] Since 1992, Mobil scientists (J.S.Beck, J.C.Vartuli, W.J.Roth, et al., J.Am.Chem.Soc., 1992, 114:10834-10843) used nanostructure self-assembly technology for the first time to prepare Since MCM-41, a mesoporous silica with uniform channels and adjustable pore diameters, mesoporous molecular sieves have attracted widespread attention. However, pure silica mesoporous materials are inert to most reactions, so active sites need to be introduced into silica-based mesoporous materials to make them catalytically active. The coordination and oxidation state of active species have a great influence on its catalytic performance, and the synthesis of silica-based mesoporous molecular sieve materials containing uniform species is very i...

AI Technical Summary

Problems solved by technology

Since mesoporous materials such as KIT-6 are usually synthesized under strong acid conditions (pH2 o 5 (c) Precipitation (I.E.Wachs, DaltonTrans., 2013, 42, 11762-11769), which prevents it from entering the framework of mesoporous molecular sieves. It has been reported in the literature that a higher content of vanadium species can be introduced into MCM under alkaline conditions In the framework of -41 mesoporous molecular sieve

However, it is very difficult to synthesize KIT-6 materials at pH>3

Therefore, it is still a great challenge to introduce vanadium species into the framework of mesoporous molecular sieves and maintain a highly ordered mesoporous structure.

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