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分别以NH_4H_2PO_4和H_3PO_2作为磷源,采用等体积浸渍-程序升温还原法制备了Ni_2P/Si O_2催化剂,采用H_2-TPR、XRD、CO化学吸附、NH_3-TPD和H_2-TPD等表征手段并结合月桂酸甲酯加氢脱氧反应评价,研究了还原温度对H_3PO_2作为磷源制备Ni_2P/Si O_2催化剂的结构及催化月桂酸甲酯脱氧性能的影响,并与以NH_4H_2PO_4作为磷源制备的催化剂进行了比较。研究表明,随还原温度提高,以H_3PO_2为磷源制备的Ni_2P/Si O_2催化剂中Ni_2P晶粒尺寸及CO吸附量增加,但催化剂表面磷含量及酸量减少;其催化月桂酸甲酯脱氧反应的性能呈提高趋势,这与其表面Ni位增多及表面P含量逐渐减少密切有关。与以NH_4H_2PO_4为磷源所制备的Ni_2P/Si O_2催化剂相比,以H_3PO_2为磷源所制备的Ni_2P/Si O_2更有利于催化月桂酸甲酯的加氢脱氧路径,可能与其表面具有较强的酸性有关。
Ni_2P / Si O_2 catalysts were prepared by the same volume impregnation-temperature programmed reduction method using NH_4H_2PO_4 and H_3PO_2 as the phosphorus sources respectively. The catalysts were characterized by H_2-TPR, XRD, CO chemisorption, NH_3-TPD and H_2-TPD, The effects of reduction temperature on the structure of Ni_2P / Si O_2 catalyst and the catalytic demethylation of methyl laurate were studied at the reduction temperature. The effects of reduction temperature on the catalyst prepared with NH_4H_2PO_4 as the phosphorus source were also studied . The results show that the Ni 2 P / Si O 2 catalyst prepared with H 3 PO 4 as a source of phosphorus increases the grain size and the amount of CO adsorbed, but decreases the content of phosphorus and the amount of acid on the surface of the catalyst. The catalytic effect of methyl laurate deoxygenation The performance is increasing, which is closely related to the increase of Ni surface and the decrease of surface P content. Compared with Ni_2P / Si O_2 catalyst prepared from NH_4H_2PO_4 source, Ni_2P / Si O_2 prepared from H_3PO_2 source is more favorable for the hydrodeoxygenation of methyl laurate, which may be related to its surface Acid related.