Open AccessNew catalysts for coal processing: Metal carbides and nitrides. Third semiannual report, July 17, 1996--January 17, 1996
Author(s) -
S. Ted Oyama,
David F. Cox
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/479183
Subject(s) - hydrodesulfurization , carbide , nitride , molybdenum , catalysis , chemisorption , materials science , sulfidation , metal , metallurgy , inorganic chemistry , coal , x ray photoelectron spectroscopy , analytical chemistry (journal) , chemistry , chemical engineering , sulfur , nanotechnology , layer (electronics) , organic chemistry , engineering
Unsupported molybdenum nitride (Mo{sub 2}N) and molybdenum carbide supported on alumina (Mo{sub 2}C/Al{sub 2}O{sub 3}) were compared against commercial sulfided MoS{sub 2}/Al{sub 2}O{sub 3} and Ni-Mo-S/Al{sub 2}O{sub 3} for hydrotreating coal-derived gas oil at 633 K (360 {degrees}C) and 13.7 MPa (2000 psig). When the catalytic rates were compared on the basis of active sites measured by chemisorption, the nitrides and carbides were estimated to have activities as much as five times that of Ni-Mo-S/Al{sub 2}O{sub 3} and MoS{sub 2}/Al{sub 2}O{sub 3}. The comparison was based on sites titrated by CO on the carbide and nitride and by O{sub 2} on the sulfided catalysts. The gas oil product quality from the carbide and nitride catalysts was significantly better than the thermal blank, indicating that the materials were active under practical hydrotreating conditions. X-ray photoelectron spectroscopy analysis after reaction of the Mo{sub 2}N and Mo{sub 2}C/Al{sub 2}O{sub 3} catalysts indicated that surface sulfiding was not extensive