Ag-Fe3O4 magnetic nano catalyst and its application in phenylethene epoxidation

Abstract

The invention belongs to the field of magnetic catalysts, and particularly relates to Ag-Fe3O4 magnetic nano-catalysts compounded under the action of polymers and their application in a styrene catalytic epoxidation system. The synthesis method is to use Fe3Cl6·6H2O and AgNO3 as raw materials to synthesize Ag-Fe3O4 composite magnetic nano-catalyst in ethylene glycol system containing NaAc by solvothermal technology with the assistance of polymer PVP; this catalyst can be used to use TBHP as oxidant, Styrene epoxidation system with toluene as solvent. The preparation method of the present invention is simple, the reactants are cheap and easy to obtain, the solvent pollution is small, the synthesis time is low, the catalyst can be conveniently separated from the reaction system under the action of an external magnetic field, and the problem that the non-magnetic nano-catalyst is difficult to recover is solved. The catalyst showed excellent catalytic activity and stability for styrene epoxidation, the yield of ethylene oxide was 84.0%, and there was no deactivation phenomenon after repeated use.

Description

technical field [0001] The invention belongs to the field of magnetic catalysts, in particular to a magnetic nano-composite catalyst and application, which refers to Ag-Fe composited under the action of polymers 3 O 4 Magnetic nanocatalyst and its application in styrene catalytic epoxidation system. Background technique [0002] Heterogeneous catalysts play an important role in chemical and fine chemical processes due to their easy separation from catalytic reaction systems. It is well known that the smaller the particle size of heterogeneous catalysts, the higher the catalytic activity they show. Due to the large specific surface area of ​​nanoscale catalysts, a large number of active sites are exposed on the surface, so that the reactant molecules can be close to the active sites of the catalyst. It is fully contacted at the "molecular level", thus showing a catalytic activity far superior to the corresponding bulk materials, and there are many related reports. However,...

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Problems solved by technology

However, it is precisely because the particle size of nanocatalysts is very small (1nm=10-9m) that they have an obvious disadvantage: it is difficult to be removed from the reaction system by traditional centrifugation and filtration methods. separation, which makes the recovery of nanocatalysts an engineering difficulty

Currently, designing and synthesizing highly efficient, recyclable, and liquid-phase catalysts for the epoxidation of styrene remains a major challenge.

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