周振华,阎卫宏,张耀军,魏昭彬,邓存,辛勤.MoO_3/(TiO_2-SiO_2)催化剂的表面分散状态及催化性能的研究[J].分子催化,1996,(3):
MoO_3/(TiO_2-SiO_2)催化剂的表面分散状态及催化性能的研究
Studies on Dispersion State and Catalytic Activities of MoO 3/(TiO 2 SiO 2)
  
DOI:
中文关键词:  气相流动吸附法,LRSTPR分散状态,分散阈值加氢脱硫
英文关键词:Grafting, LRS, TPR, Dispersion state, Dispersion threshold, HDS
基金项目:福建省自然科学基金资助项目
周振华  阎卫宏  张耀军  魏昭彬  邓存  辛勤
中国科学院大连化学物理研究所,福建宁德师范专科学校化学系
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中文摘要:
      用气相流动吸附法(grafting)制备复合载体,用浸渍法(impregnation)制备MoO3/(TiO2-SiO2)催化剂.应用LRS和TPR技术研究MoO3在复合载体TiO2-SiO2表面的分散状态,发现TiO2在SiO2表面的分散可增强MoO3与载体之间的相互作用,提高MoO3在载体表面的分散阈值.催化剂的活性评价在固定床中压反应装置中进行,以69%(wt)环己烷、20%(wt)的环己烯、10%(wt)的苯、1%(wt)的噻吩混合液为反应液,以噻吩、环己烯和苯的转化率作为催化剂的HDS、HYD、BHD活性指标.结果表明,经TiO2调变后,其HDS、HYD、BHD活性都较原来高,对于不同MoO3含量的MoO3/(TiO2-SiO2),HDS、HYD催化性能测试发现,当MoO3含量低于分散阈值时,其HDS、HYD活性随MoO3含量线性上升,但在高于分散阈值后,几乎保持不变.该催化剂对苯几乎没有加氢活性,显示出很高的环己烯加氢选择性.通过分散阈值与其HDS、HYD活性的关系可知,分散阈值可作为优化加氢精制催化剂配比的一个重要参数,具有较强的实际意义
英文摘要:
      The surface dispersion state and reduction behavior of MoO 3/(TiO 2 SiO 2) were studied by LRS, TPR and their thiophene hydrodesulfurization (HDS), cyclohexene hydrogenation (HYD) and benzene hydrogenation (BHD) activities were measured in a fixed bed reactor with 0.5 g of catalyst at 2.8 MPa H 2 pressure. The results are as follows: (1) The incorporation of TiO 2 not only promoted the dispersion of MoO 3 on complex support but also enhanced the interaction between MoO 3 and complex support, therefore, the dispersion threshold of MoO 3 was raised. (2) The TPR results indicated that the reducibility of Mo 6+ on the complex carrier increased, while that on SiO 2 decreased at high temperature. (3) It is observed that catalytic activities linearly increased with MoO 3 content up to dispersion threshold and then remained almost constant independent of the MoO 3 content. (4) The measurement of the catalytic activities shows that the activities of MoO 3/(TiO 2 SiO 2) are higher than that of MoO 3/SiO 2. TiO 2 can greatly improve the HDS, HYD activity of MoO 3/SiO 2.
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