摘要
分别以正硅酸乙酯和伯胺表面活性剂为原料和模板剂成功制备HMS介孔分子筛,经负载活性组分后得到Pt-Sn/HMS催化剂并将其应用于丙烷脱氢制丙烯反应。探究合成过程中伯胺表面活性剂碳链长度及水和乙醇的比例对HMS介孔分子筛孔结构的影响。XRD和N_(2)吸附-脱附等分析结果表明,模板剂链长增长时,介孔分子筛孔径、孔壁厚、比表面积及孔容均增大。适当的水/乙醇比例有利于获得更大比表面积和孔体积的介孔分子筛,并表现出更有序的介孔结构。丙烷脱氢制丙烯反应评价和热分析等表征结果表明,HMS介孔分子筛孔道特征直接影响Pt-Sn/HMS催化剂的催化性能。使用孔体积且比表面积较大的HMS样品作为载体制备的脱氢催化剂在丙烷脱氢反应中表现出优异的催化活性。性能最优的Pt-Sn/HMS-0.60-16催化剂上,平均丙烷转化率达到46.5%,平均丙烯选择性为94.1%,反应24 h后积炭量仅为质量分数3.4%。
HMS mesoporous molecular sieves were synthesized successfully using tetraethyl orthosilicate(TEOS)and primary amines as raw materials and template,respectively.After loading with active components,Pt-Sn/HMS catalysts were prepared and applied to propane dehydrogenation to propylene.The effects of the carbon chain length of primary amine surfactant and the ratio of water to ethanol on the pore structure of HMS mesoporous molecular sieves were investigated.The results of XRD and N_(2)adsorption-desorption showed that the pore diameter,wall thickness,surface area and pore volume of mesoporous molecular sieves increased with the increase of template chain length.The appropriate ratio of water to ethanol is beneficial to obtain mesoporous molecular sieves with larger surface area and pore volume,and more ordered mesoporous structure.The results of the catalytic reaction and thermal analysis show that,the pore characteristics of HMS mesoporous molecular sieves could directly affect the catalytic performance of the Pt-Sn/HMS catalysts.Only when the HMS sample with large surface area and pore volume was used as support,the Pt-Sn/HMS catalyst could show excellent catalytic performance in the reaction of propane dehydrogenation.The Pt-Sn/HMS-0.60-16 catalyst shows the optimal catalytic performance in propane dehydrogenation to propylene,with an average propane conversion of 46.5%,an average propylene selectivity of 94.1%,and a carbon deposition of only 3.4%(mass fraction)after 24 h reaction.
作者
江珊
刘红梅
刘东兵
Jiang Shan;Liu Hongmei;Liu Dongbing(SINOPEC(Beijing)Research Institute of Chemical Industry Co.,Ltd.,Beijing 100013,China)
出处
《工业催化》
CAS
2023年第9期49-55,共7页
Industrial Catalysis
关键词
催化剂工程
HMS介孔分子筛
PT催化剂
丙烷脱氢
丙烯
catalyst engineering
HMS mesoporous molecular sieve
Pt catalyst
propane dehydrogenation
propylene
