Yingli Wang

Methanol aromatization over HZSM-5 catalysts modified with different zinc salts

Abstract HZSM-5 catalysts modified with various Zn salts, namely zinc sulfate, zinc acetate, zinc nitrate, and zinc chloride, were prepared using an impregnation method. The resultant catalysts were characterized by X-ray diffraction, N 2 adsorption, thermogravimetry-mass spectrometry, temperature-programmed desorption of NH 3 , and infrared spectroscopy using pyridine as the probe molecule. The methanol-to-aromatic (MTA) performance over the modified catalysts was investigated. The results showed that the type of Zn species in the catalyst significantly influenced the catalyst surface acidity. The distribution of acid sites and Zn species in the HZSM-5 catalyst modified with zinc sulfate effectively improved the MTA performance.

Improved Selectivity toward Light Olefins in the Reaction of Toluene with Methanol Over the Modified HZSM‐5 Catalyst

Light olefins and para‐xylene were produced with high selectivity in the reaction of toluene with methanol over a modified HZSM‐5 catalyst. Ordered mesoporous structure and weaker acidic sites led to significant contribution to the selectivity toward para‐xylene. By means of a single‐pulse reaction and the temperature‐programmed surface reaction, it was confirmed that the presence of toluene and as‐produced xylene shortened the reaction induction period and reduced the formation temperature of ethylene and propylene, which was beneficial to improve the selectivity toward light olefins, particularly ethylene.

Preparation and characterization of ultrafine Fe-Cu-based catalysts for CO hydrogenation

Abstract The ultrafine particles of a new style Fe-Cu-based catalysts for CO hydrogenation were prepared by impregnating the organic sol of Fe(OH) 3 and Cu(OH) 2 onto the activated Al 2 O 3 , in which the organic sol of Fe(OH) 3 and Cu(OH) 2 were prepared in the microemulsion of dodecylbenzenesulfonic acid sodium(S)/ n -butanol(A)/toluene(O)/water with V (A)/V (O) = 0.25 and W (A)/W (S) = 1.50. This catalyst was characterized by particle size analysis, XRD and TG. The results of particle size analysis showed that Fe(OH) 3 particles with a mean size of 17.1 nm and Cu(OH) 2 particles with an average size of 6.65 μm were obtained. TG analysis and XRD patterns suggested that 673 K is the optimal calcination temperature. CO hydrogenation produced C + 2 OH with a high selectivity above 58 wt% by using the ultrafine particles as catalyst, and the total alcohol yield of 0.250 g·ml −1 ·h −1 was obtained when the contents of Al 2 O 3 and K were 88.61 wt% and 1.60 wt%, respectively.

HY Zeolite Modified by Liquid Silane Deposition and Its Catalytic Activity in Selective tert-Butylation of Naphthalene

Abstract HY zeolites were modified by chemical liquid deposition with i -C 4 H 9 Si(OC 2 H 5 ) 3 , followed by hydrothermal treatment. The samples were characterized by X-ray diffraction, N 2 adsorption and pulse mass analysis to investigate the influence on framework structure, specific surface area, pore diameter and adsorption behaviors. The catalytic performances of HY zeolite and the modified samples in the alkylation of naphthalene with tert -butyl alcohol were also evaluated. The results showed the modification of HY zeolite did not change framework structure but increased specific surface area, decreased average pore diameter, and reduced the size of pore opening. Catalytic activity of the modified HY zeolite catalyst for tert -butylation of naphthalene was decreased compared with that of HY zeolite catalyst while shape-selectivity of 2,6-di- tert -butylnaphthalene (2,6-DTBN) was increased obviously, the highest 2,6-DTBN/2,7-DTBN ratio of 6.62 obtained.