Abstract
Ni2P/SBA-15 precursors with Ni2P loadings of 25 wt% and initial P/Ni of 0.8 were prepared using nickel nitride as nickel source, diammonium hydrogen phosphide as phosphorus and mesopore molecular sieve SBA-15 as support. Then Ce was introduced into the Ni2P/SBA-15 precursor. The novel mesoporous Ce-Ni2P/SBA-15 catalysts were prepared after temperature-programmed reduction in flowing H2. The structure was characterized by X-ray diffraction, N2 adsorption–desorption isotherms, NH3 temperature-programmed desorption and X-ray photoelectron spectroscopy. The catalytic activities for the hydrodesulfurization (HDS) of dibenzothiophene (DBT) were evaluated. The results showed that only Ni2P phase was formed in Ce-Ni2P/SAB-15 catalysts with Ce loadings of 0–5 wt%. Ni2P and Ni12P5 phases were existed in 7 wt% Ce-Ni2P/SBA-15 catalyst. The surface area and pore volume increased when Ce was added to Ni2P/SBA-15 catalyst. The strength of the acid sites and total acid amount of Ce-Ni2P/SBA-15 catalysts increased with increasing Ce loadings. Ce existed in the form of Ce3+and Ce4+, Ni existed in the form of Ni2+ and Niδ+, and P existed in the form of Pδ− and P5+. The addition of Ce to the Ni2P/SBA-15 catalyst decreased Niδ+ concentration in Ni2P/SBA-15 catalyst. The activity for HDS of DBT over Ni2P/SBA-15 catalysts was affected by the addition of Ce at 300–340 °C. The catalysts exhibited a good catalytic performance of deep hydrodesulfurization of dibenzothiophene and the conversion of DBT can reach 98.9 % at 380 °C. Biphenyl was the main product over Ce-Ni2P/SBA-15 catalysts and cyclohexylbenzene was the main product over Ni2P/SBA-15 catalyst at 380 °C.
Highlights
Automobile industrial developments in the worldwide have increased the environmental pollution
For 7 % Ce-Ni2P/SBA-15 catalyst, the diffraction peak of the Ni12P5 phase appeared, which was located at 2h = 38.48, 41.68 and 48.98 (PDF-22-1190). This indicated that Ni2P and Ni12P5 phases existed in 7 % Ce-Ni2P/SBA-15
The diffraction peak of Ce species was not shown with the increasing of Ce loadings in Ce-Ni2P/SBA-15 catalysts, indicating that Ce was well dispersed in SBA-15 or Ce concentration was too low
Summary
Automobile industrial developments in the worldwide have increased the environmental pollution. The surface area and pore volume increased when Ce was added to Ni2P/SBA-15 catalyst. The strength of the acid sites and total acid amount of Ce-Ni2P/SBA-15 catalysts increased with increasing Ce loadings. The addition of Ce to the Ni2P/SBA15 catalyst decreased Nid?
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