Influences of cerium on structure and catalytic performance of n-heptane hydroisomerization of Ni-HPW/MCM-48

By means of X-ray diffraction (XRD), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), NH3-temperature (NH3-TPD), Py-infrared (Py-IR) and thermogravimetry-differential scanning calorimetry (TG/DTA) techniques, the influences of Ce on the structure, acidity, stability and hydroisomerization performance of Ni-HPW/MCM-48 and Ni-HPW/Ce-MCM-48 catalysts were studied. The results showed that introduction of appropriate content of Ce into MCM-48 could improve the crystallinity, acidity and stability of mesoporous silica. The acidity and stability of the Ni-HPW/Ce-MCM-48 catalyst was also increased. Besides, the catalytic performance of the Ni-HPW/Ce-MCM-48 catalyst for n-heptane hydroisomerization was promoted. The conversion and selectivity of the Ni-HPW/Ce-MCM-48 catalyst reached 41% and 91% respectively at the preparation conditions of 4 wt.% Ni, 20 wt.% HPW, 0.03 Ce/Si molar ratio.

Comparison of catalytic performance of Ni-HPW/MCM-48 (1), Ni-HPW/Ce-MCM-48-0.01 (2), Ni-HPW/Ce-MCM-48-0.03 (3) and Ni-HPW/Ce-MCM-48-0.05 (4) (catalyst 0.2 g, reduction temperature=673 K, reduction time=4 h, reaction temperature=553 K, WHSV=3.52 h−1, n(H2)/n(n-C7)=12)Figure optionsDownload full-size imageDownload as PowerPoint slide