Hydrodesulfurization of dibenzothiophene over siliceous MCM-41-supported nickel phosphide catalysts

Wang, Anjie; Ruan, Lifeng; Teng, Yanguo; Li, Xiang; Lu, Mohong; Ren, Jing; Wang, Yao; Hu, Yaozhong

doi:10.1016/j.jcat.2004.09.022

Cited by 110 publications

(66 citation statements)

References 19 publications

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“…The peaks for reduction of RuO2 appeared at 112 and 138 in the Ru catalyst, and shifted to higher temperatures with increasing P/Ru ratio. The same trend was observed in the TPR profiles of the Ni _ P 18), 23) and Rh _ P 58) catalysts. These findings suggest that phosphate cover the RuO2 particles, resulting in decreased reducibility of RuO2.…”

Section: Ruthenium Phosphidesupporting

confidence: 79%

Noble Metal Phosphides as New Hydrotreating Catalysts: Highly Active Rhodium Phosphide Catalyst

Kanda

Uemichi

2015

J. Jpn. Petrol. Inst.

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Metal phosphide has been widely investigated as a hydrotreating catalyst. The preparation and performance of noble metal phosphide catalyst was examined to develop new phosphide hydrotreating catalysts. The supports affect reducibility of phosphate as a P precursor. Since phosphate does not strongly interact with SiO2 and TiO2 supports, Rh2P was easily formed on these supports. Furthermore, formation of Rh2P enhanced the hydrodesulfurization (HDS) activity of supported Rh _ P catalyst. The type of noble metal (NM) and P/NM ratio also strongly affect formation of noble metal phosphide and HDS activity. Excess P facilitates formation of noble metal phosphides at lower reduction temperature. In contrast, excess P causes the aggregation of noble metal phosphide and formation of phosphorus rich noble metal phosphide. Rh _ 1.5P/SiO2 catalyst had high and stable activity for HDS reaction. Furthermore, this catalyst showed significantly higher hydrodenitrogenation (HDN) activity than sulfided NiMoP/Al2O3 catalyst. Therefore, Rh2P has great potential as a new hydrotreating catalyst.

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Section: Ruthenium Phosphidesupporting

confidence: 79%

Noble Metal Phosphides as New Hydrotreating Catalysts: Highly Active Rhodium Phosphide Catalyst

Kanda

Uemichi

2015

J. Jpn. Petrol. Inst.

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“…[13] The oxide precursors were pelletized and sieved to 20-35 mesh. The synthesis of Ni 2 P was carried out in a dielectric barrier discharge (DBD) reactor [14] consisting of a quartz tube and two electrodes ( Figure S1 in the Supporting Information).…”

Section: Methodsmentioning

confidence: 99%

The Synthesis of Metal Phosphides: Reduction of Oxide Precursors in a Hydrogen Plasma

et al. 2008

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Phosphorus can react with most elements of the periodic table to form different classes of phosphides, ranging from ionic for the alkali and alkaline-earth elements to metallic or covalent for the transition elements and covalent for the main-group elements. Among them, InP and GaP (III-V semiconductors) have various applications in telecommunications, optoelectronic devices and solar cells, [1,2] while transition-metal phosphides are attractive candidates for high-performance catalytic, electronic, and magnetic applications. [3] A variety of methods for synthesizing bulk metal phosphides, including direct reaction of the appropriate elements for prolonged periods at high temperature, reaction of phosphine with metals or metal oxides, reduction of metal phosphates by hydrogen, electrolysis of molten metal phosphate salts, solid-state metathesis, thermal decomposition of single-source precursors, and self-propagation high-temperature synthesis, are known. [4][5][6] These methods typically require extremely high reaction temperatures (sometimes above 1000 8C) and/or long reaction times. Metal phosphides can be obtained under milder conditions in a solvothermal approach, but this method is not feasible for the deposition of metal phosphides on supports, and in cases where yellow phosphorus and sodium are employed, care must be taken to ensure the rigorous absence of oxygen and water. [7] Only two methods, namely the reduction of metal phosphates by H 2[4] and the phosphidation of metals or metal oxides with PH 3 /H 2 , [5] are generally feasible for the preparation of supported transition-metal phosphides for use as hydrotreating or hydrogenation catalysts. Supported metal phosphides are usually prepared by the reduction method due to the high toxicity of PH 3 . Nevertheless, the conversion of oxide precursors to phosphides is neither thermodynamically nor kinetically favorable. Since the formation of Ni 2 P from the oxides by means of the temperature-programmed reduction (TPR) method (Scheme 1) is thermodynamically unfavorable, the forward reaction has to be aided by high temperature and low water vapor pressure.[8] Thus, Ni 2 P can only be obtained at a low heating rate (e.g. 1 8C min À1 ) and a high H 2 flow velocity to purge the water (by-product) off the solid surface. The forward reaction is slow because the H 2 molecules must be split into hydrogen atoms, therefore the metal oxide must first be reduced and then spilt-over hydrogen atoms can reduce the phosphorus oxide, followed by a solid-state reaction to form the metal phosphide. As a consequence, Ni 2 P can only be prepared by means of the TPR method above 550 8C.Herein we describe a new strategy for synthesizing metal phosphides that uses nonthermal H 2 plasma as the reduction medium instead of the H 2 used in the TPR method. Highenergy electrons collide inelastically with hydrogen molecules in the plasma and transfer their energy to the latter, which leads to the production of excited hydrogen species and ions with a significantly higher reduction abilit...

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“…To avoid the steps of passivation and re-reduction, and to preserve the surface structure, the in-situ reduction approach has been proposed (Scheme 1) 11) . Figure 2 compares the activities of Ni2P/MCM-41 prepared by reductionpassivation-reduction and by in-situ reduction in the HDS of DBT.…”

Section: In-situ Reductionmentioning

confidence: 99%

Metal Phosphides as High-performance Hydrotreating Catalysts

Wang

Sun

et al. 2015

J. Jpn. Petrol. Inst.

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Hydrodesulfurization of dibenzothiophene over siliceous MCM-41-supported nickel phosphide catalysts

Cited by 110 publications

References 19 publications

Noble Metal Phosphides as New Hydrotreating Catalysts: Highly Active Rhodium Phosphide Catalyst

Noble Metal Phosphides as New Hydrotreating Catalysts: Highly Active Rhodium Phosphide Catalyst

The Synthesis of Metal Phosphides: Reduction of Oxide Precursors in a Hydrogen Plasma

Metal Phosphides as High-performance Hydrotreating Catalysts

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