Synthesis of HTLcs modified by K_(3)PO_(4)for side chain alkylation of toluene with methanol

摘要

A series of calcined HTLcs catalysts were prepared and modified with potassium phosphate by impregnation method to clarify the influence of catalyst alkalinity on the side chain alkylation of toluene with methanol for synthesis of ethylbenzene and styrene.The catalysts were characterized by X-ray diffraction(XRD),N_(2)physical adsorption-desorption,Fourier-transform infrared spectroscopy(FT-IR),Scanning electron microscopy(SEM),X-ray photoelectron spectrometry(XPS),NH_(3)temperature-programmed desorption(NH_(3)-TPD)and CO_(2)temperature-programmed desorption(CO_(2)-TPD).It was found that the selectivity of styrene was highest(39.25%)when the K_(3)PO_(4)loading was 7.5 wt%.And the total yield of styrene and ethylbenzene could reach 65.08%with 10 wt%K_(3)PO_(4)loading.This might due to the fact that the addition of K_(3)PO_(4)could adjust the acid and basic sites of catalysts.In addition,appropriate strength and amount of basic sites were favorable to producing more styrene.