Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (6): 1236-1241.doi: 10.3866/PKU.WHXB201703281

• ARTICLE • Previous Articles     Next Articles

Influencing Mechanism of Cyclohexene on Thiophene Adsorption over CuY Zeolites

Zhou-Sheng MO1,Yu-Cai QIN2,Xiao-Tong ZHANG2,Lin-Hai DUAN2,Li-Juan SONG1,2,*()   

  1. 1 College of Chemistry & Chemical Engineering, China University of Petroleum(East China), Qingdao 266555, Shandong Province, P. R. China
    2 Key Laboratory of Petrochemical Catalytic Science and Technology of Liaoning Province, Liaoning Shihua University, Fushun 113001, Liaoning Province, P. R. China
  • Received:2016-11-25 Published:2017-05-19
  • Contact: Li-Juan SONG E-mail:lsong56@263.net
  • Supported by:
    National Natural Science Foundation of China(21376114);National Natural Science Foundation of China(21476101);Major Program of Petroleum Refining of Catalyst of PetroChina Company Limited(10-01A-01-01-01)

Abstract:

A CuY zeolite prepared by liquid phase ion exchange was characterized by X-ray photoelectron spectroscopy, pyridine in situ Fourier transform infrared (in situ FTIR) spectroscopy, and ammonia temperature programmed desorption. The effect of cyclohexene on the adsorption of thiophene over the prepared CuY zeolite was explored by in situ FTIR. In particular, the role of the zeolite's Br?nsted acidity was investigated in the adsorption process. The results show that the percentage of Cu+ on the surface of the CuY zeolite can reach 77%. The surface acidity of the CuY zeolite mainly comprises medium and strong Br?nsted acidity and Lewis acidity. According to the adsorption results, cyclohexene negatively influences thiophene adsorption on the Br?nsted or Lewis acid sites in CuY by competitive adsorption. Although polymerization of thiophene and cyclohexene can occur easily on the HY or REY zeolites, the presence of Br?nsted acids in the CuY zeolite was not sufficient to polymerize either thiophene or cyclohexene. This difference may be caused by an anti-synergistic effect between the Cu ions of the CuY zeolite and neighboring Br?nsted acid sites, the result of which inhibits the polymerization of adsorbed thiophene and cyclohexene.

Key words: In-situ FTIR spectroscopy, Br?nsted acidity, Competitive adsorption, Anti-synergistic effect

MSC2000: 

  • O643