Naphthalene Hydrogenation Saturation over Ni₂P/Al₂O₃ Catalysts Synthesized by Thermal Decomposition of Hypophosphite

Abstract

A series of Ni 2 P/Al 2 O 3 catalysts with different Ni 2 P loadings were synthesized via thermal decomposition of hypophosphite and employed for naphthalene hydrogenation saturation. Results showed that Ni 2 P loading greatly affected Ni 2 P particle size and the number of active sites of the as-synthesized catalysts, which was derived from the variable interaction between POx and Al 2 O 3 . When the hydrogenation saturation reaction was performed at 300 °C, 4 MPa, a H 2 /oil volume ratio of 600, and a liquid hourly space velocity (LHSV) of 3 h −1 , 98% naphthalene conversion and 98% selectivity to decalin were achieved over Ni 2 P/Al 2 O 3 catalysts with 10 wt % Ni 2 P. The superior naphthalene hydrogenation saturation performance was ascribed to the large specific surface area (169 m 2 •g −1 ), small Ni 2 P particle size (3.8 nm), and the high number of exposed active sites (CO sorption 30 μmol•g −1 ), which were beneficial to the adsorption and diffusion of the reactant molecules on the catalyst.

Influence of Reduction Temperature on the Structure and Naphthalene Hydrogenation Saturation Performance of Ni2P/Al2O3 Catalysts

“…The isovolumetric impregnation method was employed to synthesize the catalysts as described in our previous work [18], and Ni loading was kept at 10 wt.%. Firstly, a certain amount of nickel acetate tetrahydrate (Ni(CH 3 COO) 2 •4H 2 O, analytical pure, Tianjin Kemiou Chemical Reagent Co., Ltd., Tianjin, China) and ammonium hypophosphite (NH 4 H 2 PO 2 , analytical pure, Aladdin, Shanghai, China) were dissolved in the proper amount of distilled water according to the P/Ni molar ratio of 2 to obtain a uniform solution.…”

“…It has been proven that Ni 2 P has the highest catalytic activity among many phosphide catalysts and Ni 2 P catalysts have been applied to aromatic hydrogenation reactions [15][16][17][18][19][20]. Weber et al found that the higher the dispersion of Ni 2 P, the better the hydrodesulfurization performance of the catalyst [21].…”

Effects of CeO2, TiO2, and TiO2-CeO2 Supports on Catalytic Performance of Ni2P in Hydrodeoxygenation of Anisole

“…The following step was demethoxylation and dehydroxylation to form cyclohexane as a final product. It has been reported that metal phosphide catalysts show remarkably high activity and stability during hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrodearomatization (HDA) of petroleum feedstocks. − Oyama and Lee reported a relationship between active sites and the structure of metal phosphide. The crystal structure of Ni 2 P adopts a hexagonal form ( a = b = 0.5859 nm, c = 0.3382 nm), which consists of two types of metal atoms with tetrahedral coordination Ni (1) and square pyramidal coordination Ni (2). , The authors extrapolated the results from the EXAFS characterization with Ni (1) and Ni (2) sites, concluding that they were responsible for different outcomes in HDS.…”

Synthesis of Ni/NiAlOx Catalysts for Hydrogenation Saturation of Phenanthrene

“…Polycyclic aromatic hydrocarbons (PAHs) are predominantly present in coal tar, whose direct discharge and insufficient combustion would cause environmental pollution (Hayakawa et al, 2000;Li and Suzuki 2010). Therefore, the treatment of PAHs has gained undivided attention, and hydrogenation of PAHs is an attractive method as it effectively yields the cycloalkanes which can be blended into the jet fuels to improve the volumetric calorific value and combustion performance (Yoon et al, 1996;Zhang et al, 2018;Jing et al, 2020;Jia et al, 2021). However, it is quite difficult to achieve complete saturation while performing the hydrogenation of PAHs with more aromatic rings, and in particular, the saturation of the final aromatic ring is more difficult (Beltramone et al, 2008).…”