Effect of In-Situ Synthesis of Ni@B-HZSM-5 by Nitrilotriacetic Acid Coordination Assistance on Alkylation of Benzene With Methanol
In this work,nitrilotriacetic acid ion(NTA3-)was used to coordinate with Ni2+in strong alkaline solution for the in-situ synthesis of B-Ni-supported ZSM-5 zeolite(Ni@B-HZSM-5).The catalyst was characterized by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray fluorescence spectroscopy(XRF),N2 adsorption-desorption,pyridine adsorption IR spectra(Py-IR),NH3 temperature programmed desorption(NH3-TPD)and H2 temperature programmed reduction(H2-TPR).Moreover,the alkylation of benzene with methanol was evaluated in a fixed-bed reactor,and was compared to that of Ni/HZSM-5 zeolite prepared using impregnation method.The results indicate that the Ni@B-HZSM-5 catalyst prepared by in-situ synthesis exhibits uniform distribution of B and Ni,abundant weak acid and suitable hydrogenation capability,and the side reaction of methanol hydrogenation to methane is inhibited to some extent.Under the temperature of 460 ℃,H2 pressure of 0.4 MPa,n(benzene)∶n(methanol)of 1.2∶1 and MHSV of 2 h 1,4％Ni@B2-HZSM-5 has good catalytic activity in alkylation of benzene with methanol,the benzene conversion can reach up to 46.4％,the total selectivity for toluene and xylene is 95.9％,the selectivity of C8 aromatics is 35.1％,and the molar fraction of ethylbenzene in C8 aromatics is 6.1％,exhibiting excellent stability,which has better catalytic performance than Ni/HZSM-5 zeolite prepared using impregnation method.
NETL
NSTL
万方数据
