LIU Jia, JIANG Guiyuan, ZHAO Zhen, et al. Preparation of Pt/TiO2/ZSM-5 catalyst for catalytic conversion of n-butane[J]. CIESC Journal, 2016, (8): 3363-3373. DOI: 10.11949/j.issn.0438-1157.20160464.
LIU Jia, JIANG Guiyuan, ZHAO Zhen, et al. Preparation of Pt/TiO2/ZSM-5 catalyst for catalytic conversion of n-butane[J]. CIESC Journal, 2016, (8): 3363-3373. DOI: 10.11949/j.issn.0438-1157.20160464.DOI:
Pt/TiO2/ZSM-5 catalyst with dehydrogenation-cracking bifunctionality catalytic activity was prepared by modifying ZSM-5 zeolite with titanium dioxide (TiO2) via sol-gel method and then loading Pt to the titanium modified ZSM-5 zeolite by incipient impregnation method. The as-prepared catalyst was characterized by means of XRD
N2 adsorption-desorption
TEM
XPS and NH3-TPD to analyze crystal structure
pore properties
morphology
valence states of active metal and acid properties of the catalyst
and the catalytic performance for the cracking of n-butane into light olefins was investigated. The results showed that the introduction of titanium dioxide provided additional acid sites to ZSM-5 zeolite
especially increasing the strong acid centers and enhancing the activation of n-butane. In addition
after reduction in hydrogen atmosphere
the partially reduced Ti3+ species was generated which was catalyzed by platinum due to the strong metal-support interaction (SMSI) between Pt and TiO2. The formation of appropriate amount of Ti3+ species enhanced the electron density around Pt
and thus weakened the adsorption of ethene and propene on Pt atoms. After reduction by hydrogen at 450℃
n-butane conversion of 76.1% and yield of light olefins (C2=-C3=) of 50.9% were achieved at the reaction temperature of 625℃ over Pt/10TiO2/ZSM-5 catalyst
which was 16.7% and 12.6% higher than those of Pt/ZSM-5 catalyst