Study On The Composite Material Of Metal Cobalt Powder/Electroless Copper Plating For Preparation,Characterization And Catalytic Performance In Cyclohexene Oxidation

The study of catalytic cyclohexene oxidation gradually has been paid attention inacademia and industry filed, its oxidation products have a wide range of applications in thepetroleum chemical industry, fine chemical and polymer materials and other fields.Cyclohexene molecule has a susceptible oxidation C=C bond and a plurality of α-H atom,if oxidation reaction occurs on the C=C bond, oxidation products are cyclohexanol diol,epoxy cyclohexane, aldehyde and carboxylic acid. If oxidation reaction occurs on the α-Hatom, could generate2-cyclohexene-1-alcohol,1-2-cyclohexene-ketone or cyclohexenebase peroxide and other high value-added down-stream products. At present, the study ofcatalytic oxidation of cyclohexene mainly using solid acid, organic metal complexes andorganic metal salts as the catalyst, although the conversion and selectivity are improvedgreatly, but most of the reaction need to use the organic solvent or phase transfer agent, andmost of the reaction use hydrogen peroxide and tert-butyl hydrogen peroxide and hydrogenperoxide as oxidant, there is significantly higher cost and environment pollution problems.In this subject, Co/Cu-ELD, Ti/Cu-ELD，C/Cu-ELD and Al/Cu-ELD composite catalystswere prepared by electroless copper plating method, under solvent-free conditions andmolecular oxygen as an oxidant, the catalytic properties of cyclohexene oxidation reactionwas studied. The main innovation point is that composite materials of metal cobalt powder/electroless copper plating were prepared for the first time, and discusses the relationshipbetween its structure and the performance of the catalytic oxidation of cyclohexene. Themain research work is as follows:Use metal cobalt powder as substrate, sodium hypophosphite as the reducing agent,using the method of electroless copper plating prepared different Cu/Co mol ratio ofcomposite catalyst, its composition and structure was studied by ICP, XRD, BET and SEM.Under solvent-free conditions, oxygen as oxidant, the catalytic activity of Co/Cu-ELD forcyclohexene oxidation reaction was studied, For Co/Cu-ELD-5catalyst, it has bettercatalytic activity, Using TEM and XPS characterization the composition and properties,and investigates the effect of parameters such as reaction temperature, reaction time andcatalyst dosage for catalytic oxidation of cyclohexene.In the experimental conditions ofreaction temperature is349k, time is6h and catalyst dosage is11.7mg, the conversionrate of cyclohexene is46.3%, the total selectivity of epoxy cyclohexane, cyclohexene-1-2 alcohol,1-2-cyclohexene-ketone,1,2-ring adipic alcohol and cyclohexene hydrogenperoxide is89.8%. In the cycle test, the activity of the catalyst is not stable, speculatedreason may be that the weak force of copper and cobalt in composite materials. In addition,use titanium powder, aluminum powder and activate carbon as the matrix respectively,prepared Ti/Cu-ELD, Al/Cu-ELD and C/Cu-ELD catalyst, and the catalytic activity werecompared with Co/Cu-ELD-5.The results showed that the catalyst activity ofCo/Cu-ELD-5is much higher than the other catalysts, which was attributed to thesynergetic effect between cobalt powder and copper particles.