Preparation of supported nickel phosphide catalyst by solvothermal method and its hydrodesulfurization performance
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摘要: 以廉价的三苯基膦(PPh3)为磷源,以三正辛胺(TOA)为液相反应体系,溶剂热法制备了负载型Ni2P/MCM-41催化剂,并采用XRD、BET、CO吸附、XPS和TEM等手段对制备得到的催化剂进行了表征。该方法的合成温度为330 ℃,反应在常压下进行,比程序升温还原法(H2-TPR)所需的还原温度至少低300 ℃,比传统的溶剂热法合成原料更廉价。以二苯并噻吩(DBT)为模型化合物,比较了所制备的Ni2P/MCM-41催化剂与H2-TPR法制备的催化剂结构以及加氢脱硫(HDS)性能。结果表明,溶剂热法能够降低催化剂表面上P物种的集聚,从而得到较大比表面积的Ni2P催化剂(690 m2/g);促进小尺寸、高度分散的Ni2P活性相的生成;制得的催化剂的HDS活性明显高于H2-TPR法催化剂,在反应温度340 ℃,质量空速2.0 h-1,H2/油=500(体积比),3.0 MPa的条件下,Ni2P/M41-R催化剂DBT转化率达到96.8%,较H2-TPR法高10.6%。
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关键词:
- 溶剂热法 /
- Ni2P /
- 二苯并噻吩(DBT) /
- 加氢脱硫(HDS)
Abstract: The supported Ni2P/MCM-41 catalyst was prepared by a solvothermal method using triphenylphosphine (TPP) as a cheap phosphorus material and tri-n-octylamine (TOA) as the coordinating liquid reaction system. The catalysts were characterized by X-ray diffraction (XRD), N2-adsorption, CO uptake, X-ray photoelectronspectroscopy (XPS) and transmission electron microscopy (TEM). The solvothermal synthesis was performed at atmospheric pressure and 330 ℃, at least 300 ℃ lower than the temperature for preparing the corresponding catalysts by temperature-programmed reduction (H2-TPR) method. The structure and hydrodesulfurization (HDS) performance of the as-prepared Ni2P/MCM-41 catalyst are compared with those prepared by H2-TPR, with dibenzothiophene (DBT) as a model compound. The results showed that the solvothermal method can decrease the aggregation of P species on the catalyst surface so as to achieve a Ni2P catalyst with high surface area (690 m2/g) and then promote the formation of small and highly dispersed Ni2P active phase. The catalyst from solvothermal synthesis exhibits distinctly a superior HDS performance to that prepared by H2-TPR method. Under the conditions of 340 ℃, 3.0 MPa, a H2/oil volume ratio of 500(volume ratio), and a weight hourly space velocity (WHSV) of 2.0 h-1, the conversion of DBT reaches 96.8% over the catalyst from solvothermal synthesis, which is 10.6% higher than that over the catalyst prepared via H2-TPR. -
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