Catalytic pyrolysis of oleic acid to BTX over Ni-modified nano-ZSM-5 zeolite
摘要
Hierarchical zeolites can provide multidimensional spatial networks, thereby holding significant potential as catalysts for BTX production from biomass pyrolysis. In this study, nano-ZSM-5 zeolite (ZX-X) with a hierarchical pore structure was synthesized using glycine as a growth inhibitor. Due to the exceptional ability of Ni to cleave C–C and C–H bonds, Ni modification was performed on the Z30-0.2 catalyst. The effects of glycine and Ni loading on the morphology and pore structure of the zeolites were systematically investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption–desorption. The results demonstrated that the particle size of 10 wt% Ni-Z30-0.2 zeolite ranged from 200 to 300 nm, with a BET surface area of 314 m2/g and abundant mesopores. The NH3-TPD results showed that the acid amount of 10 wt% Ni-Z30-0.2 was 0.72 mmol/g. The prepared zeolite was employed in a fixed-bed reactor to catalyze the pyrolysis of oleic acid for the production of benzene, toluene, and xylene (BTX). The introduction of metal Ni significantly enhanced the BTX yield. At 500 ℃, the average BTX yield achieved with the 10 wt% Ni-Z30-0.2 catalyst was 19.4 wt%, which was higher than that of the zeolite without Ni loading.