Molybdenum (at 2.8, 3.3, 4.0 and 4.7 atom
s nm<
sup>−2
sup>) and cobalt (Co/(Co + Mo) ratio
s of 0.3, 0.4 and 0.5) were impregnated on wide-pore ZrO<
sub>2
sub>–TiO<
sub>2
sub> mi
xed oxide
s (30–70) prepared with
solvo-thermal treatment (80 °C, 1 day). Material
s characterization compri
sed N<
sub>2
sub> phy
si
sorption, XRD, thermal analy
se
s, and UV–vi
s DRS, Raman, and IR
spectro
scopie
s. For impregnated dried material
s (non-calcined) at concentration
s beyond 3.3 atom nm<
sup>−2
sup> and activated by
sulfiding (H<
sub>2
sub>S/H<
sub>2
sub>, 400 °C) no further improvement in activity in dibenzothiophene (DBT) hydrode
sulfurization (HDS) (at 5.59 MPa,
T = 320 °C) wa
s ob
served. Thu
s, monolayer Mo di
sper
sion wa
s a
ssumed at that content. The aforementioned formulation wa
s cho
sen to be promoted by Co at different concentration
s, the maximum HDS activity being found for
sulfided cataly
st with Co/(Co + Mo) = 0.4. Neverthele
ss, the promotion ob
served by Co addition wa
s small (by a factor of
src="http://www.
sciencedirect.com/
scidirimg/entitie
s/223c.gif" alt="not, vert,
similar" title="not, vert,
similar" border="0">3.2). The activity trend
s ob
served in the DBT HDS were well confirmed in the hydrotreatment of a real feed
stock (
straight-run ga
soil). Dibenzothiophene reliably repre
sented the behavior of organo-
sulfur compound
s pre
sent in the middle di
stillate, at the reaction condition
s u
sed in thi
s study where
sterically hindered compound
s remained unreacted in the hydrotreated ga
soil.