Application On ZnO And Metallocene Loaded On Silica Gel Microspheres And Their Catalytic Properties

The excellent performance of silica gel has led to its widespread application in various fields.In the preparation of composite catalysts,silica gel is an excellent carrier.For example,loading zinc oxide semiconductor nanoparticles on the surface of silica gel microspheres can greatly improve the photocatalytic efficiency of zinc oxide.Loading zinc oxide on the surface of silica gel microspheres not only allows good dispersion of zinc oxide and reduces its usage,but also allows the catalyst to be recycled for reuse.Loading metallocene on the surface of silica gel microspheres not only greatly improves the catalytic activity of the catalyst,but also effectively avoids the bimolecular deactivation of metallocene catalysts,improving the stickiness of the product.By modifying the surface of silica gel and grafting metallocene structures to form composite catalysts,the occurrence of catalyst detachment can be effectively prevented,and its catalytic activity can be improved.In this paper,silica gel microspheres were used as the carrier for semiconductor zinc oxide nanoparticles to synthesize ZnO@silica gel composite catalysts.As the carrier for metallocene catalysts,metallocene@silica gel composite catalysts were synthesized.The catalytic activity of the composite catalysts in organic dye photocatalytic degradation and olefin polymerization reactions was studied in depth.The details are as follows:Specifically,regular-shaped silica gel microspheres with a particle size of approximately 0.5 μm were prepared using ethyl orthosilicate as the raw material and the glucose molecular spacing method.ZnO@silica gel-supported organic dye photocatalytic degradation catalysts were synthesized using these silica gel microspheres as carriers and acetic acid zinc as the zinc source.The degradation performance of the composite catalyst under UV light irradiation for Safranine T was systematically studied,including the effect of different composite catalyst morphologies and properties,different zinc oxide loading amounts,composite catalyst usage,and UV light irradiation time on the degradation effect of Safranine T.It was found that under the same conditions of mass(10 mg)and reaction time(40 min),the catalytic degradation rate of Safranine T by ZnO@silica gel composite catalysts(approximately 91%)was much higher than that of pure ZnO particles(approximately 46%).When the molar percentage of loaded ZnO was 4.6%,20 mg of composite catalyst completely degraded 100 m L of 10 mg/L Safranine T at room temperature within 40 min.Using silica gel as a carrier,different organic reagents were used to modify the surface of silica gel,and then metallocene was synthesized in situ to chemically bond to the surface of silica gel microspheres.The catalytic activity of the composite catalyst in ethylene polymerization was investigated.Specifically,the surface of the silica gel microsphere was first amidefunctionalized(the amino group was grafted onto the silica gel surface using aminopropyltriethoxysilane as the raw material,and then the amino group was converted to an amide group by reacting with acetyl chloride).Metallocene structures were synthesized in situ based on this modification group’s amide bond coordination effect to chemically bond the metallocene to the carrier surface,thus preparing the composite catalyst.In this paper,the catalytic activity of the prepared bonded composite catalyst in ethylene polymerization reaction was compared with that of the composite catalyst formed by zirconium dichloride directly supported on the organic modified silica gel surface.The results showed that the composite catalyst formed by chemical bonding on the silica gel surface has higher catalytic activity in ethylene polymerization reaction.