Summary: | 博士 === 國立中央大學 === 化學工程研究所 === 82 === The interaction of vanadium and nickel in USY and REY zeolites
, and the effect of matrix on the resistance of vanadium and
nickel poison of USY and REY zeolites have been investigated by
X-ray diffraction, nitrogen sorption, Fourier-transform
infrared spectroscopy, temperature-programmed reduction,
temperature-programmed desorption of ammonia, n-hexane cracking
and thermal gravimetric analysis. Alumina, magnesia-alumina,
alumina-aluminum phosphate and magnesia-alumina-aluminum
phosphate were used as matrics of zeolite. There is an the
inhibition effect for vanadium and nickel to affect the
catalytic and physical-chemical properties of USY and REY
zeolites. Nickel can inhibit the destruction of zeolite caused
by vanadium. Vanadium can suppress the coke formation due to
the presence of nickel. The presence of matrix can increase the
resistance of zeolite to steam deactivation. Magnesia-alumina
matrix demonstrate the highest ability to capture vanadium.
This can be attributed to the basicity of magnesia. Alumina-
aluminum phosphate has a strong interaction with nickel. The
stronger the nickel-matrix interaction, the less poison effect
of nickel. In addition, the strong interaction leads to the
decrease in nickel''s ability to retard the destruction of
zeolite structure by vanadium.
|