Synthesis Of Ferrierite(FER) By Dual-template Method And Its Study On Catalysis Of Glycerol Ester Of Rosin

Ferrierite（FER）is a kind of molecular sieve with layered structure,with a unique porous system and good thermal/hydrothermal stability.However,the small pore size leads to carbon deposition and blockage and limits the diffusion,which results in deactivation of the molecular sieve and restricts the application in catalytic reaction.One of the solutions is preparing FER molecular sieve with multistage porous structure.At present,the dual-template method of introducing surfactant has attracted extensive attention because of the efficient introduction of new porous structure in the synthesis of molecular sieve,which is more flexible and diverse.FER molecular sieves were synthesized by single template hydrothermal method.On this basis,FER molecular sieves were synthesized by dual-template method.The crystallization process and synthetic samples were investigated by the factors such as Si O₂/Al₂O₃,Na₂O/Si O₂,EDA/Si O₂,H₂O/Si O₂,crystallization temperature and crystallization time.The results showed that the changes of various factors obviously affected the physicochemical properties of sample FER molecular sieves.When the Si/Al ratio was high or the alkalinity and water content were low,the solubility of silicon source in the system were reduced,which left incomplete crystallizing in synthesis reaction.The solubility of the system reduced with high water content and failed to reach the saturation state,which affected the crystallization results.The experimental results also showed that EDA played a decisive role in guiding the topology of FER,but the content of template should not be too high to affect crystallinity of crystal.When there is not enough crystallization temperature or crystallization time,FER molecular sieve will not crystallize completely,resulting in waste of raw materials,otherwise the occurring of crystal transformation led to failure of synthesis for pure phase FER molecular sieve.On the basis of single template hydrothermal synthesis method,this paper introduces different surfactants(CTAB,CTAC;C₁₂DGPB,C₁₄DGPB and C₁₆DGPB)as second template agents,synthesize FER molecular sieve by dual-template hydrothermal method,and the products were applied to the synthesis of glycerol ester of rosin.The results showed that the multistage pore structure was successfully introduced into the FER molecular sieve by dual-template hydrothermal method.Compared with the molecular sieve synthesized by the single template hydrothermal method,the specific surface area increased while the crystallinity reduced,the grain morphology changed,the layered structure opened or destroyed to varying degrees,which led to a better catalytic performance.Comparison of the crystallization products（FB and FC）with CTAB and CTAC showed that Br?can better assist the long hydrophobic group of surfactant than Cl?,improved the porous structure and catalytic performance of FER molecular sieve.The results of comparing the crystallization products（FC12,FC14 and FC16）with C₁₂DGPB,C₁₄DGPB and C₁₆DGPB found that a longer hydrophobic carbon chain of Cn DGPB accounted for a smaller the particle size of the product,and a better catalytic performance of Cn DGPB for glycerol ester of rosin.