TY - JOUR
T1 - Characterization of Pd catalysts supported on USY zeolites with different SiO2/Al2O3 ratios for the hydrogenation of naphthalene in the presence of benzothiophene
AU - Zheng, Jian
AU - Guo, Ming
AU - Song, Chunshan
PY - 2008/4
Y1 - 2008/4
N2 - A series of ultra-stable Y-type (USY) zeolites with different SiO2/Al2O3 ratios in the range of 10-80 were used as supports for preparing Pd/USY at 2 wt% Pd loading. The FT-IR of hydroxyl groups of USY zeolites, the n-butylamine chemisorption and the temperature-programmed desorption were used in combination to characterize the zeolite acidity. TPR, H2-TPD and chemisorption using H2 were used to characterize the Pd reduction and dispersion. The hydrogenation of naphthalene was conducted at 200 °C in the presence of benzothiophene at different sulfur/metal ratios. The hydrogenation activity, selectivity, and the sulfur tolerance strongly depended on the SiO2/Al2O3 ratio (thus the acidity) of the zeolites. The activity decreased with increasing SiO2/Al2O3 in this range. The IR and n-butylamine TPD showed that both the amount and strength of Brönsted acidity decreased with the increase of the SiO2/Al2O3 ratio. The good relationship between the acidity modification and catalytic performance suggests that the sulfur tolerance of Pd/USY zeolite might be due to the desired metal-support interaction, which resulted in larger amount of electron-deficient Pd. However, as shown in TGA and TPO-IR studies, the higher hydrogenation performance on more acidic zeolite also caused higher amount of carbonaceous species on the catalyst.
AB - A series of ultra-stable Y-type (USY) zeolites with different SiO2/Al2O3 ratios in the range of 10-80 were used as supports for preparing Pd/USY at 2 wt% Pd loading. The FT-IR of hydroxyl groups of USY zeolites, the n-butylamine chemisorption and the temperature-programmed desorption were used in combination to characterize the zeolite acidity. TPR, H2-TPD and chemisorption using H2 were used to characterize the Pd reduction and dispersion. The hydrogenation of naphthalene was conducted at 200 °C in the presence of benzothiophene at different sulfur/metal ratios. The hydrogenation activity, selectivity, and the sulfur tolerance strongly depended on the SiO2/Al2O3 ratio (thus the acidity) of the zeolites. The activity decreased with increasing SiO2/Al2O3 in this range. The IR and n-butylamine TPD showed that both the amount and strength of Brönsted acidity decreased with the increase of the SiO2/Al2O3 ratio. The good relationship between the acidity modification and catalytic performance suggests that the sulfur tolerance of Pd/USY zeolite might be due to the desired metal-support interaction, which resulted in larger amount of electron-deficient Pd. However, as shown in TGA and TPO-IR studies, the higher hydrogenation performance on more acidic zeolite also caused higher amount of carbonaceous species on the catalyst.
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U2 - 10.1016/j.fuproc.2007.11.025
DO - 10.1016/j.fuproc.2007.11.025
M3 - Article
AN - SCOPUS:40849100223
SN - 0378-3820
VL - 89
SP - 467
EP - 474
JO - Fuel processing technology
JF - Fuel processing technology
IS - 4
ER -