Water gas shift activity of Co-Mo/MgO-Al2O3 catalysts presulfided with ammonium sulfide

Water–gas shift activity of K-promoted (Ni)Mo/γ-Al2O3 systems in sulfur-containing feed

“…Sulfided Mo-based supported systems have been designed as sulfur-resistant WGS catalysts. A major part of the studies are related to the structure and activity of Co-Mo catalysts, both unpromoted [11][12][13][14][15] and promoted by alkaline metals [16][17][18][19][20]. To our knowledge, unpromoted Ni-Mo catalysts [21,22] or that promoted by alkaline metals [23] are so far less investigated.…”

Effect of support modification on the characterization and catalytic activity of Mo/Al2O3 catalysts

“…Lian et al [9] prepared Co-Mo/MgO-Al 2 O 3 catalyst and found that the appropriate increase of the Mg/Al atomic ratio favors the dispersion of Mo on the surface of the support; this dispersion enhances the interaction between active Mo components and the support. In another study, MoO 3 -doped Ce-AlO x mixed oxide catalysts were prepared by the simple co-precipitation method and their activity was studied for selective reduction of NO with NH 3 [10].…”

Mechanistic Study of Forming Either Cyclic or Linear Sulfur‐Clusters from Thermal Decomposition of Thiourea Under Two Distinct Conditions

“…[9] For instance, sulfur levels of on-road diesel fuel will be reduced to 15 ppm in the US or even 10 ppm in the European Union by 2010. [12] In order to remove sulfur in oil refining process, crude oils are usually hydrocracked and desulfurized over a catalyst made from molybdenum and two iron group metals, such as CoO-MoO 3 /Al 2 O 3 , NiO-MoO 3 /Al 2 O 3 , [13] Co-Mo-K/Al 2 O 3 , Co-Mo/MgO-Al 2 O 3 [14] and NiMoW/Al 2 O 3 [15] due to their high activity in a broad temperature range (200-500°C) and good sulfur-resistance. [12] In order to remove sulfur in oil refining process, crude oils are usually hydrocracked and desulfurized over a catalyst made from molybdenum and two iron group metals, such as CoO-MoO 3 /Al 2 O 3 , NiO-MoO 3 /Al 2 O 3 , [13] Co-Mo-K/Al 2 O 3 , Co-Mo/MgO-Al 2 O 3 [14] and NiMoW/Al 2 O 3 [15] due to their high activity in a broad temperature range (200-500°C) and good sulfur-resistance.…”

“…[10] Such specifications will lower the profitability of oil companies and retard their growth so that oil companies unavoidably face both operational and economic challenges, [11] because depletion of high-grade oil reserves has forced petroleum industry to use crudes that have increasingly high sulfur contents. [14] This is because catalysts in sulfide state have high catalytic efficiency, and such state also protects catalysts from deactivation due to their reduction into base metals (e.g., Mo, Co, Ni). However, commercial Mo-based catalysts are available often in oxide forms without much activity, and will become effective only after they are pre-sulfurized to the sulfide state.…”

“…However, commercial Mo-based catalysts are available often in oxide forms without much activity, and will become effective only after they are pre-sulfurized to the sulfide state. In contrast, the ex-situ method is conducted via impregnation of inactive catalysts with alkylpolysulfides followed by H 2 activation, [14] and is simple, highly efficient and less polluting. [16] Therefore, the presence of a sulfur-containing reagent is critical for the activity of catalyst.…”