Ni2P/TiO2的制备及其对苯加氢反应的催化性能

采用程序升温还原方法制备了TiO2负载的晶态Ni2P催化剂。用X射线衍射（XRD）及低温N2吸附（BET）等技术对样品的物相、比表面积等性质进行了表征。以苯气相加氢为模型反应考察了Ni2P/TiO2催化剂加氢性能，并对Ni2P负载量、前驱体中P的质量分数对催化剂的物相及性能的影响进行了研究。实验结果表明， TiO2负载的晶态磷化镍催化剂上，Ni2P是主要物相。Ni2P/TiO2催化剂对苯加氢反应具有较高的活性、选择性以及良好的稳定性能。Ni2P/TiO2制备对催化剂的性能有影响。Ni2P负载量增加，催化剂的活性先升高后降低，Ni2P负载量为12%时催化剂活性较高。催化剂前驱体中P的质量分数越高，制备出的催化剂对苯加氢反应的稳定性越好，但随前驱体中P的质量分数增加，催化反应的活性先升高，后降低。与Ni2P/SiO2比较，Ni2P/TiO2催化剂具有较高的活性和稳定性。

Preparation of Ni2P/TiO2 catalyst and its reactivity for benzene hydrogenation

Transition metal phosphides have recently been reported as a new class of high activity hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) catalysts. Among them, Ni2P has better HDS and HDN activity. The surface area of unsupported Ni2P catalysts is rather low (< 1m2/g). To increase the active surface area, the dispersion of Ni2P on a high surface support is needed. SiO2 is widely used as support of the Ni2P catalysts. TiO2 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 Ni2P catalysts on TiO2 were prepared via temperature programmed reduction. The structure characteristics of samples have been characterized by means of X ray powder diffraction（XRD），N2 adsorption (BET) and temperature programmed reduction (H2 TPR). Benzene hydrogenation was chosen as a model reaction to investigate the influences of Ni loading, initial Ni/P mole ratio. Results showed that Ni2P was the main phase on the TiO2 supported catalysts. Ni2P/TiO2 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 Ni2P loading，the activity of the Ni2P/TiO2 catalyst increased firstly and then decreased. Benzene conversion reached a maximum with Ni2P loading of about 12%. The activity and stability of the Ni2P/TiO2 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 Ni2P/SiO2, Ni2P/TiO2 catalysts had much better activity and stability in benzene hydrogenation reaction.