Hydrogenation Of Naphthalene Over MCM-41Supported Highly Dispersed Pt And Mo-based Nitride, Phosphide Catalysts

In recent years, with the imposition of more stringent environmental regulations and the growingdemand for high and the growing demand of cleaner diesel fuels, dearomatization of petroleum fractions isbecoming more important to society, and is playing a significant role in the modern refinery industry.Removing the aromatics in diesel oil not only can reduce harmful gas emissions, but also can improve thestability of the fuels product. Therefore, it attracts considerable attention for aromatics saturation to developnew catalysts and processes. So this paper mainly do the following three aspects:Firstly, platinum nanoparticle catalyst supported on MCM-41were prepared by glycol chemicalreduction method of PtC14·6H2O solution in of PVP. The structures of the catalysts were determined byBET, XRD, TEM. The results indicate that mono-size，high dispersed and well controlled Pt particles couldbe formed on Pt-PVP/MCM-4catalyst and their size could decrease and distribution is more narrow withthe increase of PVP/Pt mole ratio. The catalytic performance of supported Pt catalysts were evaluated innaphthalene hydrogenation; the relationship between the catalytic performance and their structure anddispersion were investigated too. The Pt-5PVP/MCM-41catalyst exhibits excellent hydrogenation activityin naphthalene hydrogenation reaction due to that Pt particles are smaller particle size and high dispersion,namely more Pt surface atomic number.Secondly, MoxN（x=1and2, γ-Mo₂N and δ-MoN）/MCM-41and Mo₂N/MCM-41were prepared usinga temperature programmed nitridation method. Ni-MoxN/MCM-41, Ni-Mo₂N/MCM-41were prepared byimpregnating with Ni salt solution and H2reduction. The structures of the catalysts were determined byBET, XRD, TEM, EDX. Their catalytic properties were evaluated through the naphthalene hydrogentionand compared with Ni/MCM41with similar metal loadings. The results showed that the activities ofnickel-molybdenum nitride catalysts supported on MCM-41were superior to Ni/MCM-41catalyst, due tothe synergistic effect of nickel and molybdenum nitride. The Ni-MoxN/MCM-41catalyst exhibited themost excellent catalytic property and selectivity to decalin, which may be attributed to the introduction ofthe MoN.Finally, the supported molybdenum phosphide and Ni-based catalysts were prepared using atemperature programmed reduction method. These catalysts were characterised by BET, XRD et al. andevaluated by naphthalene hydrogenation. The results show that the no-MoP/MCM-41catalyst exhibitedhigher hydrogenation activity in the hydrogenation of naphthalene than ca-MoP/MCM-41catalyst, whichmay be attributed to high dispersion and a single MoP structure. The supported molybdenum phosphidecatalyst showed the high tetraline selectivity to full hydrogenation products and selectivity to tetraline up to100%.