Synthesis, Characterization, and Hydrodesulfurization Properties of Silica-Supported Molybdenum Phosphide Catalysts

On the surface sites of MoP/SiO2 catalyst under sulfiding conditions: IR spectroscopy and catalytic reactivity studies

“…More recently, transition metal phosphides prepared by temperature-programmed reduction (TPR) were reported to have high catalytic activity for both HDN [6][7][8][9][10][11][12][13][14][15][16][17][18] and HDS [10][11][12][13][14][15][16][17]19,20]. Among these phosphide catalysts, molybdenum phosphides (MoP, MoP/SiO 2 , and MoP/ Al 2 O 3 ) [6][7][8][9]14,15,[17][18][19] received the most attention.…”

“…The HDN and HDS activities of Mo nitride and carbide catalysts are initially high but decline with time in the presence of sulfur-containing compounds, which was explained mainly by the irreversible sulfidation of these catalysts [21][22][23] under reaction conditions. However, it is interesting to note that molybdenum phosphide catalysts show quite stable activities in hydrotreating reactions in the presence of sulfur-containing feedstock, and in some cases even exhibit increased activities with reaction time [7,8,14,15,18,19]. For example, Stinner et al [7] reported that pure MoP shows a decrease in activity in the presence of H 2 S in the HDN of o-propylaniline, but the activity increases to a higher level than that at the beginning of the reaction when H 2 S is removed.…”

“…In the hydrotreatment of a model petroleum liquid [14], MoP/Al 2 O 3 catalysts showed increased activity in the first several hours in the HDN of quinoline and later reached a stable and higher activity than the commercial NiMoS/Al 2 O 3 catalyst without loss of HDS activity. In a study of the HDS of thiophene [19], a MoP/SiO 2 (15 wt% MoP) catalyst was nearly four times more active than a sulfided Mo/SiO 2 catalyst. Interestingly, excluding a decline during the first several hours in the HDS of thiophene, the activity of the MoP/SiO 2 catalyst was found to increase monotonically with time on stream and did not achieve a steady state value even after 150 h [19].…”

Selective Hydrogenation of Acetylene over a MoP Catalyst

“…Molybdenum phosphide (MoP) is a new hydrogenation catalyst that has attracted the attention of researchers. Many studies have shown that the MoP catalyst has superior catalytic activity for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) [7][8][9] but few studies have paid any attention to their reactivity in other hydrogenation reactions such as acetylene selective catalytic hydrogenation.In this work, MoP was prepared and used for the selective hydrogenation of acetylene. Ammonium heptamolybdate (NH 4 ) 6 Mo 7 O 24 ·4H 2 O was mixed with diammonium hydrogen phosphate (NH 4 ) 2 HPO 4 in distilled water at a Mo/P molar ratio of 1.0.…”

“…Molybdenum phosphide (MoP) is a new hydrogenation catalyst that has attracted the attention of researchers. Many studies have shown that the MoP catalyst has superior catalytic activity for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) [7][8][9] but few studies have paid any attention to their reactivity in other hydrogenation reactions such as acetylene selective catalytic hydrogenation.…”