Adsorptive Performance of Template-Free Hierarchical Ni-ZSM-5 Zeolite
1. College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China;
2. Henan Engineering Research Center of Resource and Energy Recovery from Waste, Kaifeng 475004, China
Abstract Hierarchical Ni-ZSM-5 zeolites were prepared by template-free method. The crystal structure, morphology, pore structure parameters and surface acidity of zeolites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR), N2 adsorption-desorption and NH3 temperature-programmed desorption (NH3-TPD). The adsorption performance of zeolites was investigated using thiophene as model molecule and the adsorption thermodynamics and kinetics were analyzed. The results showed that the adsorption capacity of the hierarchical Ni-ZSM-5 zeolites was significantly higher than that of the microporous ZSM-5 and hierarchical ZSM-5 zeolites, and the adsorption process was affected by both diffusion and chemical adsorption. The adsorption thermodynamics indicated that the adsorption of thiophene on the surface of Ni-ZSM-5 zeolites was the dominant chemical adsorption of monolayer, and the maximum adsorption sulfur capacity was 0.342 mmol/g at 303 K. The adsorption kinetics study showed that the adsorption process conformed to the quasi-n-order kinetic model with a grade of 1.5.
