High surface area MoO3/MgO: preparation by reaction of MoO3 and MgO in methanol or ethanol slurry and activity in hydrodesulfurization of benzothiophene

On the hydrodesulfurization of FCC gasoline: a review

“…[124]). this reason Zdrazil and coworker developed a non-aqueous method for the deposition of MoO 3 on MgO [142][143][144]. More recently [121,140] they reported results on the introduction of Co(Ni) promoters on a MoO 3 /MgO starting material.…”

Synthesis, characterization and catalytic activity during hydrodesulphurization of dibenzothiophene of NiMoW catalysts supported on AlTi mixed oxides modified with MgO

“…The nature of the Mo and Ni(Co) species on supports containing MgO were evidenced by UV-Vis [26,28,30] and Raman spectroscopy [23,25,26,30,32], which showed that the presence of MoO 3 in Al 2 O 3 supported catalysts tends to disappear when the MgO is added to the alumina [28]. Additionally, it was reported that Mo and Co species are highly dispersed in small clusters on Al 2 O 3 AMgO supports [30].…”

“…Due to the fact that this type of sites exhibits higher HDS activity, it is expected to obtain better catalysts [17,18]. On the other hand, the use of magnesia (MgO) as support for HDT catalysts has been proposed in the literatures [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] because MgO will be a promoter for surface properties in the support, such as acid-base site generation and support basicity. These properties of the MgO might provide favourable interactions between the support and acidic molybdenum species (MoO 3 ) [22,24] and, consequently, improve the formation of highly dispersed sulphide species [22].…”

“…These properties of the MgO might provide favourable interactions between the support and acidic molybdenum species (MoO 3 ) [22,24] and, consequently, improve the formation of highly dispersed sulphide species [22]. Besides, a basic support should inhibit coking, which occurs over acidic Al 2 O 3 supported catalysts [22]. However, an important disadvantage of MgO is hydration, because it reacts easily with air moisture to form a mixture of Mg(OH) 2 and Mg(CO 3 ) 2 ; when it is exposed during prolonged time to ambient conditions or during aqueous impregnation [19,28]; therefore other supports or binders are required to be incorporated into it and obtain a practical support [24].…”

“…Activity of MgO-supported catalysts during HDS reactions is still a topic under discussion; some authors reported that the HDS activities of MoO 3 /MgO catalysts were lower than its Al 2 O 3 supported counterparts [28,29,32], however, other authors reported the same level or higher activities for HDS on MoO 3 /MgO [22,27], CoMo/MgOAAl 2 O 3 [24,25,30], NiMo(CoMo)/MgO [23] and NiMo/MgOAAl 2 O 3 [26] catalysts compared with catalysts supported on Al 2 O 3 . About to the hydrodesulphurization and hydrogenation functions, some works reported that the use of MgO in Al 2 O 3 allows a substantial decrease in hydrogenation function over Mo/AlAMg [28] and CoMo/AlAMg catalysts [25], however, Klicpera and Zdražil [22] reported that the MoO 3 /MgO catalysts selectivity ratio of hydrogenation/hydrogenolysis was slightly higher than that of the MoO 3 /Al 2 O 3 catalyst in the HDS of benzothiophene.…”