Abstract
A series of ZSM‐5 zeolites (SiO2/Al2O3 = 50) were desilicated by sodium hydroxide with different concentrations (0.1 mol/L, 0.3 mol/L, 0.5 mol/L and 0.7 mol/L). The crystal morphology, textural property and acidic property of the catalysts were characterized by XRD, TEM, N2 adsorption–desorption isotherm, NH3‐TPD, 27Al MAS NMR and IR spectroscopy. Meanwhile, the influence of sodium hydroxide concentration in the gasoline yield, products distribution, coke deposition in the non‐hydrocracking of diesel were studied. Results showed that mesopores were successfully induced to ZSM‐5 zeolites after desilication; more weak acid sites and Lewis acid sites (LAS) were generated; in contrast, the strong acid sites and Brønsted acid sites (BAS) were weakened, leading to an increased ratio of LAS to BAS (LAS/BAS). After alkali treatment, HZ‐0.5A exhibited the maximal conversion, yield and selectivity of gasoline; while the HZ‐0.5A‐1 AC exhibited a lower yield and selectivity. It was also observed that the amount of coke and P/O performed a positive relationship with the LAS/BAS.
Published Version
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