Abstract:
Transition metal phosphides have recently been reported as a new class of highactivity hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) catalysts. Among them, Ni2P has better HDS and HDN activity. The surface area of unsupported Ni2P catalysts is rather low (< 1m2/g). To increase the active surface area, the dispersion of Ni2P on a highsurface support is needed. SiO2 is widely used as support of the Ni2P catalysts. TiO2 is commonly used as support of catalysts. It can cause strong interaction with metal, that facilitates disperse of active components on its surface. In this paper, a series of supported Ni2P catalysts on TiO2 were prepared via temperatureprogrammed reduction. The structure characteristics of samples have been characterized by means of Xray powder diffraction(XRD),N2 adsorption (BET) and temperatureprogrammed reduction (H2TPR). Benzene hydrogenation was chosen as a model reaction to investigate the influences of Ni loading, initial Ni/P mole ratio. Results showed that Ni2P was the main phase on the TiO2 supported catalysts. Ni2P/TiO2 catalysts had high activity with 100% cyclohexane selectivity and excellent stability in benzene hydrogenation reaction. The preparation factors had great effects on the activity of benzene hydrogenation reaction. With the increase of Ni2P loading,the activity of the Ni2P/TiO2 catalyst increased firstly and then decreased. Benzene conversion reached a maximum with Ni2P loading of about 12%. The activity and stability of the Ni2P/TiO2 catalysts were also affected profoundly by the initial phosphorus content. With the increase of the initial P/Ni mole ratio,the reaction stability is better,but the steady activity increased firstly and then decreased. In comparison with Ni2P/SiO2, Ni2P/TiO2 catalysts had much better activity and stability in benzene hydrogenation reaction.