Activity and sulfidation behavior of the CoMo/Al2O3 hydrotreating catalyst: The effect of drying conditions

Maleic acid, an efficient additive for the activation of regenerated CoMo/Al2O3 hydrotreating catalysts

“…More recently, the use of citric acid as an additive has been increasingly envisaged by several authors [34][35][36][37][38][39] since this compound presents the advantage to be more costly effective than preceding chelating agents. Rinaldi et al [36] studied the addition of citric acid to CoMo/Al 2 O 3 catalysts.…”

Physicochemical properties and activity of nanopowder catalysts in the hydrodesulfurization of diesel fraction

“…Hydrofining catalysts are known to exhibit hydro genation, cracking, and dehydrogenation activities [6][7][8][9]. The acidity of a particular catalytic system appreciably influences its inclination toward breaking the C-S, C-N, C-O, and C-C bonds found in the heteroaromatic compounds that are the most tolerant to hydrogenation.…”

“…However, the question as to the structure of their active sites remains open. According to the literature data, the greatest catalytic activity is exhibited by composites whose active phase is made of MoS 2 nanocrystallites no less than 5 nm in size and linked by bridge bonds with the promoter atoms found on their side faces [6,7]. In nanopowder catalysts, the mean particle size of the nanopowder precursors of an active component is considerably higher, and its value (e.g., for Mo nanop owder) is 100 nm.…”

“…The development of Russian desulfurization cata lysts is now focused mainly on improving the conven tional Ni-(Co)-Mo(W)-S/Al 2 O 3 system, which is obtained by impregnating porous supporters with salt solutions of metal salts, with solutions of metal chelate compounds, or with solutions containing one metal from the VIII group and two metals from the VIB group, followed by the decomposing and sulfurizing of the deposited substrates [6][7][8]. At the same time, some believe that such porous catalytic systems have exhausted almost all their potential.…”

A new method for reactivating the supported deep hydrotreatment CoMo/Al2O3 and NiMo/Al2O3 catalysts after oxidative regeneration

“…We may therefore select conditions of their treat ment with complexing agents used in the preparation of catalysts such that large amounts of cobalt and molybdenum can be transferred from oxides into the form of bimetallic complexes that reside in support pores and are good precursors for the further selective formation of the Co-Mo-S type II phase during sul fidation. = 285 m 2 /g, V pore = 0.82 cm 3 /g) as described in [33], was used as our fresh reference cat alyst. After preliminary calcination in a muffle furnace at 550°C for 2 h, the fresh IK GO 1 catalyst was used as an analogue of the catalyst after oxidative regenera tion.…”