Short CommunicationA new route for synthesizing nickel phosphide catalysts with high hydrodesulfurization activity based on sodium dihydrogenphosphite
Graphical abstract
A simple and efficient approach to the preparation of Ni2P nanoparticles was presented. Bulk and supported Ni2P were successfully synthesized by heating a mixture of certain stoichiometric NaH2PO3 and NiCl2·6H2O in flowing hydrogen.
Research highlights
► A new synthetic route by heating NaH2PO3 and NiCl2•6H2O to prepare Ni2P catalysts. ► It is very easy to synthesize supported Ni2P by the method. ► The Ni2P/SiO2 synthesized by the route shows a good HDS of dibenzothiophene. ► This method is also general for synthesizing other transition metal phosphides.
Introduction
Metal phosphides possess unique physical and chemical properties which make them attractive and promising for future applications in the fields of catalysis, electronics, optoelectronics, and other magnetic applications [1]. In particular, metal phosphides present a wide range of applications of catalysis, such as hydrotreatment [1], [2], [3], [4], [5], [6], [7], [8], [9], hydrodechlorination [10], hydrazine decomposition [11], water–gas-shift reactions [12], and hydrogenation of cinnamaldehyde [13] and acetonitrile [14]. Among them, Ni2P has been focused on, showing great promise for various applications. Metal phosphides may be synthesized through the reduction of phosphates and phosphinates, solid state metathesis at high temperatures, low-temperature solvothermal methods, plasma methods, and so on [5], [6], [7], [8], [9], [10], [11], [12], [13], [14]. The temperature-programmed reduction (TPR) of nickel phosphate is usually adopted to prepare catalysts. However, the TPR method requires high temperatures and programmed reduction, thus costing much energy and long periods of time. Therefore, the development of a simple preparation method featuring mild conditions for preparing metal phosphides is an important direction for many researchers [15], [16], [17], [18], [19], [20].
In this study, we synthesize bulk and SiO2-supported Ni2P catalysts by heating a precursor in N2 at a lower temperature and shorter reaction time. The precursor is a mixture obtained by mechanically mixing a certain stoichiometric ratio of NaH2PO3 and NiCl2·6H2O. Using thermal gravimetric analysis, the reaction mechanism is studied. NaH2PO3 was observed to decompose and release phosphine before reducing nickel ions to form Ni2P. According to this reaction, other corresponding phosphides can also be synthesized via this method if nickel chloride is replaced by other metal salts. Finally, via the hydrodesulfurization (HDS) of dibenzothiophene (DBT) as the model reaction, the catalyst performance is also evaluated.
Section snippets
Synthesis of bulk and supported Ni2P
In a typical process, the catalyst precursor was prepared via a mechanical mixing method. A solid phase of 0.66 g NaH2PO3 and 0.3 g NiCl2·6H2O was mechanically mixed in a quartz boat at room temperature (the molar ratio of H2PO3−/Ni2+ is 5). The precursor was directly heated to 250 °C and kept for 1 h in a flowing 30 mL/min N2. Following cooling to room temperature in continued N2 flow, the unsupported Ni2P was passivated in a 1.0 mol% O2/N2 mixture at 20 mL/min for 3 h.
For evaluating catalytic
Synthesis of bulk and supported Ni2P
Fig. 1, Fig. 2 show the XRD patterns of the prepared samples after washing. The effects of temperature and ratio of H2PO3−/Ni2+ can be clearly seen in Fig. 1, Fig. 2, respectively. Fig. 1a shows that only the typical diffraction peaks of Ni2P (d = 5.07, 3.38, 2.93, 2.81, 2.21, 2.03, 1.92, 1.69, 1.66, 1.51, 1.46, 1.41, 1.34, 1.30, and 1.27 Å) were found when a mixture of nickel chloride and sodium dihydrogenphosphite (H2PO3−/Ni2+= 5) was heated at 250 °C. Heat treatments at lower or higher
Conclusions
In summary, we have proposed a novel and simple method based on thermal treatment of a solid mixture of Na(H2PO3)2 and NiCl2·6H2O at mild condition to synthesize bulk and SiO2-supported Ni2P catalyst. Further studies will be focused on exploring this method for the synthesis of other metal phosphides (such as CoP, FeP, MoP etc.).
Acknowledgment
This work was supported by Tianjin University of Science & Technology Project of Science Research Fund (20100206).
References (25)
J. Catal.
(2003)- et al.
J. Catal.
(2006) - et al.
Catal. Today
(2007) - et al.
Catal. Today
(2008) - et al.
J. Catal.
(2009) - et al.
J. Catal.
(2009) - et al.
J. Catal.
(2006) - et al.
J. Catal.
(2007) - et al.
J. Catal.
(2009) - et al.
J. Catal.
(2008)
J. Catal.
J. Catal.
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