摘要
采用程序升温还原方法制备了TiO2负载的晶态N i2P催化剂。用X射线衍射(XRD)及低温N2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N i2P/TiO2催化剂加氢性能,并对N i2P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,TiO2负载的晶态磷化镍催化剂上,N i2P是主要物相。N i2P/TiO2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。N i2P/TiO2制备对催化剂的性能有影响。N i2P负载量增加,催化剂的活性先升高后降低,N i2P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N i2P/SiO2比较,N i2P/TiO2催化剂具有较高的活性和稳定性。
Transition metal phosphides have recently been reported as a new class of high-activity 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 （ 〈 1 m^2/g）. To increase the active surface area, the dispersion of Ni2P on a high-surface 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 temperature-programmed reduction. The structure characteristics of samples have been characterized by means of X-ray powder diffraction （ XRD）, N2 adsorption （ BET ） and temperature-programmed reduction （ H2- TPR）. 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.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2006年第1期100-104,共5页
Journal of Fuel Chemistry and Technology
基金
江苏省材料化学工程重点实验室开放基金(KJ03016)
