In situ poisoning of the thiophene hydrodesulfurization activity of carbon-supported transition metal sulfide catalysts by phosphorus

Phosphorus Promotion of Ni(Co)-Containing Mo-Free Catalysts in Quinoline Hydrodenitrogenation

“…When phosphorus was applied by impregnation of the support with H 3 PO 4 , the effects were largely the same (16,17): strongly promoting for Ni/C; neutral for Mo/C, and negative for NiMo/C. The nature of the support appeared to play an important role, as was demonstrated by a study on alumina-based catalysts (16,18). The very low HDN activity of Ni/Al 2 O 3 and Mo/Al 2 O 3 was hardly improved by impregnation of the support with H 3 PO 4 , while the active NiMo/Al 2 O 3 catalyst became even more active.…”

“…However, the increase in activity during the HDN test indicates that the transfer of P and/or formation of Ni 2 P from the volatile P-containing compounds is a rather slow process, which continues after the pretreatment. Furthermore, it has been determined by phosphorus analysis (20) of the P/C prebed and the Ni/C catalyst that this way of preparing Ni 2 P is rather inefficient: the major part of the H 3 PO 4 passes the catalyst bed without reacting.…”

“…In earlier research we studied the effect of the addition of phosphorus on the structure and catalytic activity of supported transition metal sulfides (15)(16)(17)(18)(19)(20)(21)(22). In a study with carbon-supported TMS from the first, second, and third row, it was found that the application of P by a P/C precatalyst bed generally has a negative effect on the thiophene HDS activity (17,20).…”

“…In a study with carbon-supported TMS from the first, second, and third row, it was found that the application of P by a P/C precatalyst bed generally has a negative effect on the thiophene HDS activity (17,20). A clear exception was Ni on carbon, of which the activity was rather increased by P. The influence on the quinoline HDN activity was also tested, using carbon-supported catalysts which were supplied with P by a P/C precatalyst (16,17).…”

Transition Metal Sulfide Catalysts for Petroleum Upgrading – Hydrodesulfurization Reactions

“…Thus, H2S released forms a new vacancy on the catalyst, as reported by Ruette and Ludena (Ruette & Ludena, 1981). These catalysts show high activity for the hydrodesulfurization of thiophene, mainly sulfided NiMo-AlZrP catalysts, which exhibit comparable or even higher activity than Ni, Mo and NiMo sulfided catalysts supported on carbons (Eijsbouts et al, 1994), zeolites (Welters et al, 1994) and alumina pillared smectites (Kloprogge et al, 1993) and tested in similar conditions.…”