skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-Boron Materials

Abstract

Unsupported and silica-supported amorphous metal-boron materials (Ni-B, Mo-O-B, and Ni-Mo-O-B) were prepared by NaBH{sub 4} reduction of aqueous or impregnated metal salts. The resulting materials were characterized by a range of techniques, including conventional and time-resolved X-ray diffraction. The latter technique was used to determine the onset of crystallization of the amorphous materials during annealing in He flow and to identify the phases formed. Annealing of unsupported Ni-B resulted in the crystallization of predominantly Ni{sub 3}B, followed by Ni metal, whereas Ni-B/SiO{sub 2} formed Ni and then NiO. There was no evidence for crystallization of B-containing phases for Mo-O-B or Mo-O-B/SiO{sub 2} on annealing; instead, the predominant phase formed was MoO{sub 2}. In general, the phases formed for Ni-Mo-O-B and Ni-Mo-O-B/SiO2 were consistent with those formed in the monometallic materials, but at higher annealing temperatures. Catalysts prepared by sulfiding Ni-B/SiO{sub 2} and Ni-Mo-O-B/SiO{sub 2} materials had significantly higher thiophene HDS activities than conventionally prepared sulfided Ni/SiO2 and Ni-Mo/SiO{sub 2} catalysts, whereas a sulfided Mo-O-B/SiO{sub 2} catalyst had a dramatically lower HDS activity than a sulfided Mo/SiO{sub 2} catalyst.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930289
Report Number(s):
BNL-80993-2008-JA
Journal ID: ISSN 0021-9517; JCTLA5; TRN: US200822%%1244
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Catalysis; Journal Volume: 246; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATALYSTS; SILICA; BORON; NICKEL; MOLYBDENUM; SYNTHESIS; PHASE STUDIES; THIOPHENE; DESULFURIZATION; CATALYTIC EFFECTS; national synchrotron light source

Citation Formats

Parks,G., Pease, M., Burns, A., Layman, K., Bussell, M., Wang, X., Hanson, J., and Rodriquez, J. Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-Boron Materials. United States: N. p., 2007. Web. doi:10.1016/j.jcat.2006.12.009.
Parks,G., Pease, M., Burns, A., Layman, K., Bussell, M., Wang, X., Hanson, J., & Rodriquez, J. Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-Boron Materials. United States. doi:10.1016/j.jcat.2006.12.009.
Parks,G., Pease, M., Burns, A., Layman, K., Bussell, M., Wang, X., Hanson, J., and Rodriquez, J. Mon . "Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-Boron Materials". United States. doi:10.1016/j.jcat.2006.12.009.
@article{osti_930289,
title = {Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-Boron Materials},
author = {Parks,G. and Pease, M. and Burns, A. and Layman, K. and Bussell, M. and Wang, X. and Hanson, J. and Rodriquez, J.},
abstractNote = {Unsupported and silica-supported amorphous metal-boron materials (Ni-B, Mo-O-B, and Ni-Mo-O-B) were prepared by NaBH{sub 4} reduction of aqueous or impregnated metal salts. The resulting materials were characterized by a range of techniques, including conventional and time-resolved X-ray diffraction. The latter technique was used to determine the onset of crystallization of the amorphous materials during annealing in He flow and to identify the phases formed. Annealing of unsupported Ni-B resulted in the crystallization of predominantly Ni{sub 3}B, followed by Ni metal, whereas Ni-B/SiO{sub 2} formed Ni and then NiO. There was no evidence for crystallization of B-containing phases for Mo-O-B or Mo-O-B/SiO{sub 2} on annealing; instead, the predominant phase formed was MoO{sub 2}. In general, the phases formed for Ni-Mo-O-B and Ni-Mo-O-B/SiO2 were consistent with those formed in the monometallic materials, but at higher annealing temperatures. Catalysts prepared by sulfiding Ni-B/SiO{sub 2} and Ni-Mo-O-B/SiO{sub 2} materials had significantly higher thiophene HDS activities than conventionally prepared sulfided Ni/SiO2 and Ni-Mo/SiO{sub 2} catalysts, whereas a sulfided Mo-O-B/SiO{sub 2} catalyst had a dramatically lower HDS activity than a sulfided Mo/SiO{sub 2} catalyst.},
doi = {10.1016/j.jcat.2006.12.009},
journal = {Journal of Catalysis},
number = 2,
volume = 246,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Unsupported and silica-supported amorphous metal-boron materials (Ni-B, Mo-O-B, and Ni-Mo-O-B) were prepared by NaBH4 reduction of aqueous or impregnated metal salts. The resulting materials were characterized by a range of techniques, including conventional and time-resolved X-ray diffraction. The latter technique was used to determine the onset of crystallization of the amorphous materials during annealing in He flow and to identify the phases formed. Annealing of unsupported Ni-B resulted in the crystallization of predominantly Ni3B, followed by Ni metal, whereas Ni-B/SiO2 formed Ni and then NiO. There was no evidence for crystallization of B-containing phases for Mo-O-B or Mo-O-B/SiO2 on annealing;more » instead, the predominant phase formed was MoO2. In general, the phases formed for Ni-Mo-O-B and Ni-Mo-O-B/SiO2 were consistent with those formed in the monometallic materials, but at higher annealing temperatures. Catalysts prepared by sulfiding Ni-B/SiO2 and Ni-Mo-O-B/SiO2 materials had significantly higher thiophene HDS activities than conventionally prepared sulfided Ni/SiO2 and Ni-Mo/SiO2 catalysts, whereas a sulfided Mo-O-B/SiO2 catalyst had a dramatically lower HDS activity than a sulfided Mo/SiO2 catalyst.« less
  • A series of highly dispersed Rh-based materials have been prepared by deposition of laser-generated gas-phase clusters onto an industrial-grade alumina. While the diameter of the gas-phase metal clusters could be kept at or below 1 nm, the average diameter of the resulting supported Rh particles was always at least 1.5 nm. The reaction of the clusters with either O{sub 2} or C{sub 2}H{sub 4} failed to prevent Rh aggregation on the alumina surface. The addition of O{sub 2} upstream of the Rh target was sufficient to form bulk Rh{sub 2}O{sub 3}, whereas downstream addition of O{sub 2} or C{sub 2}H{submore » 4} to the Rh cluster was insufficient to form Rh oxide particles. Most of the Rh-containing particles further aggregated during either sulfiding or HDS testing. Nevertheless, the resulting rhodium sulfides were comparable in activity to sulfided, commercial Co-Mo or Ni-Mo catalysts on a per gram of catalyst basis and superior on a per gram of metal basis. At low loadings (0.1 wt%), the cluster-derived catalysts were more hydrogen-efficient than the commercial catalysts. 88 refs., 13 figs., 5 tabs.« less
  • Silica-supported rhodium phosphide (Rh2P/SiO2) catalysts were prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), 31P solid-state NMR spectroscopy, X-ray photoelectron spectroscopy (XPS), and chemisorption measurements. XRD and TEM analysis of a 5 wt.% Rh2P/SiO2 catalyst confirmed the presence of well-dispersed Rh2P crystallites on the silica support having an average crystallite size of 10 nm. NMR spectroscopy showed unsupported and silica-supported Rh2P to be metallic and XPS spectroscopy yielded a surface composition of Rh1.94P1.00 that is similar to that expected from the bulk stoichiometry. The 5 wt.% Rh2P/SiO2 catalyst exhibited a higher dibenzothiophene (DBT) hydrodesulfurization (HDS) activity thanmore » did Rh/SiO2 and sulfided Rh/SiO2 catalysts having a similar Rh loading and was also more active than a commercial NiAMo/Al2O3 catalyst. The Rh2P/SiO2 catalyst showed excellent stability over a 100 h DBT HDS activity measurement and was more S tolerant than the Rh/SiO2 catalyst. The Rh2P/SiO2 catalyst strongly favored the hydrogenation pathway for DBT HDS, while the Rh/SiO2 and sulfided Rh/SiO2 catalysts favored the direct desulfurization pathway.« less
  • The HDS properties of a series of Co xNi 2-xPy/SiO 2 catalysts have been investigated as a function of the Co/Ni molar ratio (for a fixed P/Me molar ratio) and of the P/Me molar ratio (for a fixed Co/Ni molar ratio). An oxidic precursor composition of Co 0.08Ni 1.92P 2.00 on the silica support yielded the bimetallic phosphide phase having the highest HDS activity, 34% higher than that of an optimized nickel phosphide catalyst prepared from an oxidic precursor having a composition of Ni 2.00P 1.60. X-ray photoelectron spectroscopy revealed Ni-rich Co xNi 2-xP y/SiO 2 catalysts to have surfacemore » enrichment of P (relative to Ni 2.00P 1.60/SiO 2 and Co 2.00P 1.00/SiO 2 catalysts) and to incorporate remarkably low amounts of S during HDS testing. The high activity of these Co xNi 2-xPy/SiO 2 catalysts is attributed to surface enrichment of P relative to nickel phosphide, which results in improved resistance to S incorporation under HDS conditions. Consistent with these findings and the solid-state chemistry evidence that suggests that Ni atoms in Ni-rich Co xNi 2-xPy/SiO 2 catalysts occupy disproportionately more pyramidal M(2) sites than tetrahedral M(1) sites, we conclude that the high site densities of these catalysts are due to Ni atoms in surface M(2) sites, which results in P-enriched surfaces that are resistant to site blockage due to S incorporation.« less
  • A series of mesoporous synthetic organo-clay complexes has been prepared by hydrothermal crystallization of gels containing silica, magnesium hydroxide, lithium fluoride, and an organic of choice, followed by calcination to remove the organics. The organic serves to impart structural order to the inorganic network that does not disappear upon its removal. The choice of organic modifier can be used to control the pore structure of the resulting mesoporous materials. Pore size distributions appear in some cases to be related to the type of polymer packing upon clay formation in situ. These materials are being explored as Co Mo hydrodesulfurization (HDS)more » catalyst supports. Preliminary HDS results show performance commensurate with commercial catalysis for the mesoporous materials when a model heavy oil feed is used (1 wt% S as dibenzothiophene in hexadecane). Temperature programmed reduction experiments of used catalysts suggest a relationship between HDS activity and ease of reduction of the CoMo/clay catalysts. Reactivity of the CoMo clay also correlates with the percentage of mesopore volume remaining after reaction. Losses in mesopore volume are largely recouped by recalcination, suggesting that reversible coke is formed inside the pore structure of clays faster than inside conventional alumina.« less