Effect of the second metal of Anderson type heteropolycompounds on hydrogenation and hydrodesulphurization properties of XMo6(S)/Al2O3 and Ni3-XMo6(S)/Al2O3 catalysts

Comparison between alumina supported catalytic precursors and their application in thiophene hydrodesulfurization: (NH4)4[NiMo6O24H6]·5H2O/γ-Al2O3 and NiMoOx/γ-Al2O3 conventional systems

“…It was found that heteropolycompounds are effective precursors of a multilayered active phase of hydrotreating catalysts. 21 Despite reports in the literature on the synthesis of heterogeneous hydrotreating catalysts from Anderson type heteropolycompounds; less emphasis has been made on the comparison of these catalysts and the conventional ones prepared at the same composition (i.e., with non-optimized Mo/ promoter contents), thus it is not yet clear how these systems work in HDS although the Ni content is considerably lower…”

Hydrogenolysis of dibenzothiophene on zinc-modified NiMoW/Al2O3 hydrotreating catalysts

“…1) reduces DBT conversion at any quantities of zinc. A possible cause of this phenomenon is a decrease in the formation of "NiMo(W)S" phase due to a competi tion between Ni 2+ and Zn 2+ , while the "ZnMo(W)S" phase has a lower activity [24].…”

CoMo/Al2O3 catalysts prepared on the basis of Co2Mo10-heteropolyacid and cobalt citrate: Effect of Co/Mo ratio

“…To confirm the composition and structure of the heteropolycompound, its elemental analysis, IR spectrum and phase composition were determined [10,14]. Decamolybdodicobaltate heteropolyacid H 6 [Co 2 Mo 10 O 38 H 4 ] (here in Co 2 Mo 10 HPA) was prepared by cations exchange of NH þ 4 using KU-2 cation exchanger [29,30].…”

“…However, a HPA, in which Co/Mo ratio is equal to 0.5, has not been found yet. It has been established [10][11][12]14,20,21] that catalysts prepared on the basis of Co(Ni) salts of HPAs are more effective than ones synthesized from ammonium salts or by conventional methods from AHM with cobalt nitrate. Because of different reactivity, sulfidation mechanism of Co 2+ cations in cobalt salt of [Co 2 Mo 10 O 38 H 4 ] 6À (Co 3 ACo 2 Mo 10 HPA) may be distinguished from Co 3+ placed into Co 2 Mo 10 HPA.…”