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采用等体积浸渍法制备了nNiMoO_x·ZSM-5单相复合体催化剂,采用XRD,NH3-TPD,BET等方法对其物相结构、表面酸性、比表面积进行了表征;以正己烷为模型反应物,在高压微反装置上对nNiMoO_x·ZSM-5催化剂的正己烷异构化反应性能进行了评价。表征结果显示,nNiMoO_x·ZSM-5单相复合体催化剂中,ZSM-5分子筛骨架结构保持完好,金属活性组分Ni和Mo以Ni Mo O x原子簇的形式定位于ZSM-5分子筛的孔道内,与分子筛的骨架氧配位形成了nNiMoO_x·ZSM-5单相复合体,引起ZSM-5分子筛的晶胞收缩,晶胞参数和晶胞体积减小;随Ni/Mo原子比的增大,nNiMoO_x·ZSM-5催化剂的酸量增加,比表面积整体变化不明显。在2.0 MPa、液态空速1.0 h-1、氢烃摩尔比4∶1的反应条件下,Ni/Mo原子比为2.0的nNiMoO_x·ZSM-5催化剂在220℃时正己烷转化率为69.6%,250℃时正己烷转化率为79.3%;随反应温度的升高,异构化选择性呈先增大后减小的趋势。
The nNiMoO_x · ZSM-5 single phase composite catalyst was prepared by the same volume impregnation method. The phase structure, surface acidity and specific surface area of the catalyst were characterized by XRD, NH3-TPD and BET. , N-hexane isomerization reaction performance of nNiMoOx · ZSM-5 catalyst was evaluated on high pressure micro-reactor. Characterization results show that the framework structure of the ZSM-5 zeolite remains intact in the nNiMoOx · ZSM-5 single-phase composite catalyst, and the Ni and Mo active metal components are localized in the pores of the ZSM-5 zeolite in the form of NiMoO x clusters , Resulting in the formation of nNiMoO_x · ZSM-5 single phase complex with the framework oxygen of the molecular sieve, resulting in the shrinkage of unit cell and the decrease of unit cell parameters and unit cell volume. With the increase of Ni / Mo atomic ratio, The acidity of nNiMoO_x · ZSM-5 catalyst increased, but the specific surface area did not change obviously. Under the reaction conditions of 2.0 MPa, liquid hourly space velocity 1.0 h-1, and hydrogen-to-hydrogen molar ratio 4: 1, the n-hexane conversion of Ni / MoOx · ZSM-5 with Ni / Mo = 2.0 was 69.6% The conversion of n-hexane was 79.3% at 250 ℃. With the increase of reaction temperature, the selectivity of isomerization increased first and then decreased.