Effect of a second metal (Co, Fe, Mo and W) on performance of Ni₂P/SiO₂ for hydrodeoxygenation of methyl laurate

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• 作者：Zhengyi Pan ; Rijie Wang ; Ziyang Nie ; Jixiang Chen ; ^{jxchen@tju.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Bimetallic phosphide ; Solid solution ; Methyl laurate ; Hydrodeoxygenation ; Decarbonylation
• 刊名：Journal of Energy Chemistry
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：25
• 期：3
• 页码：418-426
• 全文大小：2065 K

文摘

Ni₂P/SiO₂ and bimetallic NiMP/SiO₂ (M = Co, Fe, Mo, W; Ni/M atomic ratio=5) catalysts were prepared by the temperature-programmed reduction method. The catalysts and their precursors were characterized by means of UV–Vis DRS, H₂-TPR, XRD, TEM, CO chemisorption and NH₃-TPD. Their performance for the deoxygenation of methyl laurate was tested on a fixed-bed reactor. The results show that the main phase was Ni₂P in all catalysts, and M (M = Co, Fe, Mo, W) entered the lattice of Ni₂P forming solid solution. Different from Fe and Co, the introduction of Mo and W into Ni₂P/SiO₂ reduced the phosphide particle size and increased the acid amount. In the deoxygenation reaction, the turnover frequency of methyl laurate increased on the catalysts in the order of NiMoP/SiO₂, Ni₂P/SiO₂, NiWP/SiO₂, NiFeP/SiO₂ and NiCoP/SiO₂, which is influenced by the size of phosphide particles and the interaction between Ni and M (M = Fe, Co, Mo or W). The introduction of the second metal (especially Mo and W) into Ni₂P/SiO₂ promoted the hydrodeoxygenation pathway. This is mainly attributed to the interaction between Ni and the second metal. Finally, the NiMoP/SiO₂ catalyst was tested at 340 ºC, 3 MPa, methyl laurate WHSV of 14 h⁻¹ and H₂/methyl laurate molar ratio of 25 for 132 h, and its deactivation took place. We found that the catalyst deactivation mainly resulted from carbonaceous deposit rather than the sintering of metal phosphide crystallites.