Nano metal catalyst and preparation method and application thereof

Abstract

The invention discloses a nano metal catalyst and a preparation method and an application thereof. The nano metal catalyst consists of nano Pd catalyst particles, carrier of nano Pd catalyst and a crosslink polymer coat which is wrapped on the surface of the nano Pd catalyst. The preparation method of the nano metal catalyst comprises the following steps: in the inert atmosphere, reaction monomer and comonomer are undertaken the copolymerization with the nano Pd catalyst loaded by the carrier to obtain the product. The reaction of the 2,4-dimethyl-1,3-pentylene and the propenol in the catalyzing supercritical carbon dioxide medium has high selectivity and reaction activity. The method has simple preparation process, and the metal catalyst is stable; and after the reaction is ended, the catalyst can be separated from the product through the centrifugal to be repeatedly used. By adequately integrating the steric effect of the polymer coat and the particular performance of the supercritical carbon dioxide, the nano metal catalyst has promising application prospect in the catalyzing reaction.

Description

technical field [0001] The present invention relates to a nano-metal catalyst and its preparation method and application, in particular to a nano-metal catalyst supported by a cross-linked polymer coating coating carrier and its preparation method and its high-selectivity hydrogenation reaction in supercritical carbon dioxide Applications. Background technique [0002] When hydrocarbons are cracked to produce monoolefins such as ethylene, propylene, and butene, some conjugated dienes are produced. These conjugated diolefins are easy to polymerize under the action of catalysts to form colloids during the post-processing of olefins, especially in the process of olefin polymerization, which blocks the pores of the catalyst and affects the life of the catalyst. And an effective method to remove these conjugated diolefins is exactly the selective hydrogenation of conjugated diolefins to corresponding monoolefins without the generation of alkane (Munro S and ColmanP.Effect of Tol...

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Problems solved by technology

[0003] Therefore, in order to realize the selective hydrogenation of this type of conjugated diolefins into monoolefins, the inventors designed a special catalyst, that is, coated nano-metal catalysts with a polymer coating, aiming at The steric hindrance effect improves the selective hydrogenation of the double bond of the terminal group of the conjugated diene, while the internal double bond is basically not affected, and it is difficult to control a certain double bond of this kind of reactant by using a general bare metal nanocatalyst hydrogenation

However, there are two problems to be solved. One problem is how to coat the polymer stable coating on the surface of the solid-supported nano-metal catalyst, which is very difficult and challenging in terms of catalyst preparation.

Another problem is that this layer of polymer coating is difficult to diffuse the reaction substrate into the polymer coating and contact the catalyst with a general solvent, which requires a special reaction medium to swell this layer of polymer coating, and The combination of supercritical carbon dioxide performance can solve this problem very well, because supercritical carbon dioxide has the characteristics of high diffusivity, zero interfacial tension and expansion performance on polymers, which can expand the polymer layer to drive reactants and hydrogen to reach Catalyzed reaction

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