Structure-sensitivity of hydrodesulfurization of 4,6-dimethyldibenzothiophene over silica-supported nickel phosphide catalysts

PETR 31

Yuying Shu, shu@che.udel.edu1, Yong-Kul Lee, yolee@vt.edu2, and S. Ted Oyama, oyama@vt.edu2. (1) Dept. of Chemical Engineering, Virginia Polytechnic Institute & State University, Blacksburg, VA 24061, (2) Dept. of Chemical Engineering, Virginia Polytechnic Institute and State University, Randolph Hall, Blacksburg, VA 24061
The effect of surface area on the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) was studied on a series of supported nickel phosphide catalysts of low (Ni2P/SiO2-L, 96 m2 g-1), medium (Ni2P/SiO2-M, 133 m2 g-1) and high (Ni2P/SiO2-H, 208 m2 g-1) specific surface areas. The best catalyst, Ni2P/SiO2-H, gave a steady-state conversion of 99+% at 613 K, which was higher than that of the Ni2P/SiO2-M (94%) or the Ni2P/SiO2-L (76%). The order (H > M > L) correlated with the dispersion of the catalysts as measured from CO uptakes (125 vs. 99 vs. 59 µmol g-1), and the Ni2P crystallite size as determined from X-ray diffraction (6.5 vs. 7.8 vs. 10.1 nm). Extended X-ray absorption fine structure (EXAFS) and elemental analysis measurements showed that the nickel phosphide was partially sulfided and formed a surface phosphosulfide phase in the HDS reaction. The HDS reaction for this molecule is structure-sensitive.
 

2nd International Symposium on Hydrotreating/Hydrocracking Technologies
8:30 AM-11:50 AM, Monday, 11 September 2006 Palace -- Presidio Room, Oral

Division of Petroleum Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006