ISSN 0965ꢀ5441, Petroleum Chemistry, 2016, Vol. 56, No. 1, pp. 44–50. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © I.A. Sizova, A.B. Kulikov, M.I. Onishchenko, S.I. Serdyukov, A.L. Maksimov, 2016, published in Neftekhimiya, 2016, Vol. 56, No. 1, pp. 52–58.
Synthesis of Nickel–Tungsten Sulfide Hydrodearomatization
Catalysts by the Decomposition of OilꢀSoluble Precursors
I. A. Sizovaa, A. B. Kulikova, M. I. Onishchenkoa, S. I. Serdyukova, b, and A. L. Maksimova, b
aTopchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia
eꢀmail: isizova@mail.ru
bFaculty of Chemistry, Moscow State University, Moscow, Russia
Received June 5, 2015
Abstract—Nickel–tungsten sulfide catalysts for the hydrogenation of aromatic hydrocarbons have been preꢀ
pared by the in situ decomposition of an oilꢀsoluble tungsten hexacarbonyl precursor in a hydrocarbon feedꢀ
stock using oilꢀsoluble nickel salt nickel(II) 2ꢀethylhexanoate as a source of nickel. The in situ synthesized
Ni–W–S catalyst has been characterized by Xꢀray photoelectron spectroscopy. The activity of the resulting
catalysts has been studied in the hydrogenation of bicyclic aromatic hydrocarbons and dibenzothiophene
conversion in a batch reactor at a temperature of 350°C and a hydrogen pressure of 5.0 MPa. It has been
shown that the optimum W : Ni molar ratio is 1 : 2. Using the example of the hydrofining of feedstock with
high sulfur and aromatics contents, it has been shown that the synthesized catalyst exhibits high activity in
the hydrogenation of aromatic hydrocarbons.
Keywords: tungsten hexacarbonyl, oilꢀsoluble precursors, nickel–tungsten sulfide catalyst, dehydrodearomꢀ
atization, light cycle oil
DOI: 10.1134/S0965544115080174
The use of heavy oil fractions with a high concenꢀ [5–9]. Oilꢀsoluble salts, such as transition metal naphꢀ
tration of sulfur and aromatic hydrocarbons (HCs) in
oil refining, along with tightening the requirements on
the amount of these compounds in fuels, has given an
impetus to increased interest in the study of new sulꢀ
furꢀresistant catalysts for the hydrogenation of aroꢀ
matic compounds. Owing to the exceptional resisꢀ
tance to catalyst poisons, transition metal sulfides
[1]—mostly tungsten and molybdenum sulfides proꢀ
moted with cobalt or nickel—are extensively used in
hydrotreating and hydrofining processes involving
purification of feedstocks for the removal of impurities
containing hetero atoms, such as sulfur, nitrogen, and
oxygen, in a hydrogen atmosphere, the hydrogen satꢀ
uration of unsaturated HCs, and the hydrogenation of
aromatic compounds [2].
thenates, carbonyls, 2ꢀethylhexanoates, and acetylacꢀ
etonates, can be used as precursors of sulfide catalysts
[10]. Oilꢀsoluble precursors are readily dispersed in a
HC feedstock and generate catalysts with high hydroꢀ
genation ability. The general scheme of synthesis of
sulfide catalysts from oilꢀsoluble precursors distribꢀ
uted in a HC phase includes the thermal decomposiꢀ
tion of the precursor in a HC medium with a sulfiding
agent [11].
Unlike the well documented Co(Ni)–Mo [3, 9]
and Co(Ni)–Mo–W sulfide systems [12, 13], unsupꢀ
ported Ni–W–S catalysts, which must exhibit a subꢀ
stantially higher hydrogenation activity, have been
examined to a lesser extent [14] and studies of disꢀ
persed catalysts focus on their behavior in the
hydrodesulfurization [13–15] and hydroconversion of
heavy feedstock [16, 17].
In recent years, unsupported sulfide catalysts have
attracted much attention owing to their high activity
in hydrotreatment reactions [3–4]. These catalysts
have exhibited higher catalytic activity than convenꢀ
tional supported catalysts [4]. The synthesis methods
for unsupported catalysts can be divided into two main
groups: the first group involves the synthesis of an
active catalyst outside of the reaction zone (ex situ),
while the second group is based on the formation of a
catalyst directly in a HC medium (in situ). The in situ
preparation of a catalyst in the reaction medium proꢀ
vides a high sulfur content in the resulting sulfide catꢀ
In this study, we propose a method for synthesizing
a nickel–tungsten sulfide catalyst by the in situ
decomposition of the oilꢀsoluble tungsten hexacarboꢀ
nyl precursor in a HC feedstock. The catalytic properꢀ
ties in the hydrogenation reaction were studied using
model systems (naphthalene and alkylꢀsubstituted
naphthalenes with one, two, and three methyl substitꢀ
uents) as an example and in the hydrofining of light
cycle oil (LCO), representative actual feedstock with
alyst and leads to the formation of stable fine particles high sulfur and aromatics contents.
44