Research On Preparation Of Activated Carbon Supported Triphenylphosphine Catalyst By Impregnation Method And Its Performance

Triphenylphosphine with different metal formed symmetrical composition with catalytic activity to catalyze various organic reactions, but the homogeneous catalyst is difficulties separation from the product, can not be recovered is the limits of its large-scale application, the immobilization of homogeneous catalyst is an important way to solve the difficult of catalysts separation and recovery. This paper choose activated carbon and high carbon crystallization as carrier, through two-step impregnation method to product three phenyl phosphine-potassium alum / activated carbon(highly crystalline carbon) composite catalyst, and used to catalyze the aldol condensation. Using Boehm titration, scanning electron microscopy(SEM) and energy-dispersive X ray spectroscopy(EDS), X ray diffraction(XRD), infrared spectroscopy(FTIR), infrared reflectance(DRIFT), contact angle analysis, nitrogen adsorption desorption(BET), X ray photoelectron spectroscopy(XPS) and gas chromatography(GC) to characterize the catalysts and synthesis products.Used nitric acid in mass fraction of 10% on activated carbon has better modified effect.The number of oxygen functional groups on the surface of modified activated carbon was increased, especially the number of phenolic hydroxyl groups changed to 2.13 times. Directly lead to increase the impregnation yield of triphenylphosphine.Activated carbon grafted ethylenediamine and diethanolamine can produced new chemical bond imidazoline.But triphenylphosphine impregnation yield of modified were decreased.Used aquae hydrogenii dioxide about 10(wt) % on highly crystallized carbon has better modified effect,the number of the hole was increased after modified, the specific surface area increased to 1.81 times,this provides more attachment for the triphenylphosphine and potassium alum, the amount of oxygen-containing functional groups increased to 1.9 times,the impregnation yield of triphenylphosphine was increased.By two-step impregnation method to preparation of triphenylphosphine-potassium alum / activated carbon(highly crystalline carbon) composite catalyst.First dipping potassium alum and then impregnated triphenylphosphine can get high yield,Catalytic synthesis of chalcone showed that activated carbon as a carri--er have small mechanical strength, the catalyst recycling many times,the catalyst with high recovery rate. Triphenylphosphine-potassium alum/highly crystallized carbon composite catalysts have a good catalytic effect, the yield can reach up to 88.3%, the catalyst can be recycled more than 3 times, the purity of the product is as high as 97%.