Health & Environmental Research Online (HERO)


Print Feedback Export to File
7731572 
Journal Article 
Effect of carriers on physico-chemical properties and activity of Pd nano-catalyst in n-hexane isomerization 
Cam Loc Luu; Thi Kim Thoa Dao; Tri Nguyen; Thanh Huong Bui; Thi Ngoc Yen Dang; Minh Nam Hoang; Si Thoang Ho 
2013 
IOP Publishing Ltd 
BRISTOL 
4 
4 
045001 
English 
WOS:000209539100003 
In this work zeolites HY, HZSM-5 and mixes of zeolites with γ-Al 2O3 in different ratios were taken as carriers for 0.8 wt% Pd catalysts. Physico-chemical characteristics of the catalysts were determined by methods of Brunauer-Emmett-Teller (BET)-N2 adsorption, x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), hydrogen pulse chemisorption (HPC) and NH3 adsorption-desorption. The activity of catalysts was studied at 225-450 °C, at 0.1 and 0.7MPa with molar ratio of H2:n-C6H 14 = 5.92 and n-hexane concentration 9.2 mol%. Mixing of γ-Al2O3 with zeolite made acidity of catalyst weaken and led to a decrease of Pd cluster size, to an increase of Pd dispersity and a reduction of the extent of Pd in the case of catalyst Pd/HY; but for the catalyst Pd/HZSM-5 such mixing led to the reverse effect. That is why the increase of activity in the first case and the decrease of activity in the second case have been observed. It has been found that the optimal ratio of mixed carrier is γ-Al2O3: HY = 2.5:1 and the optimal calcined temperature of NH4ZSM-5 to obtain HZSM-5 is 500-550 °C. An increase of reaction pressure from 0.1 to 0.7MPa remarkably increased the activity, selectivity and stability of Pd-based catalysts. © 2013 Vietnam Academy of Science & Technology. 
n-hexane isomerization; Pd; HY; HZSM-5; mixed carriers zeolite + Al2O3