焙烧温度对加氢处理催化剂表面活性金属微区分布及其加氢反应性能的影响

Effect of calcination temperature on active metal microzone distribution on surface of hydrotreating catalyst and its hydrogenation reaction performance

制备了不同活性金属微区分布的加氢处理催化剂,采用XPS,HRTEM等方法对催化剂进行了表征,并在微型反应装置上考察了催化剂的加氢反应性能。实验结果表明,对氧化态催化剂而言,随着焙烧温度的升高,金属Mo的分散度逐渐增大,金属Ni的分散度逐渐减小;对硫化态催化剂而言,所制备催化剂上Mo^(4+)的形成占比先增加后减小,Ni物种的硫化度则逐渐减小;MoS_(2)活性相平均堆垛层数先增加后减小,平均片晶长度则先减小后增加;当焙烧温度为550~650℃时,硫化态催化剂的平均堆垛层数为3.5~3.7、平均片晶长度为3.6~3.8 nm;当焙烧温度在650℃时,催化剂加氢反应的相对芳烃饱和能力提高了4.1百分点,链烷烃和总环烷烃含量均有所增加。

Hydrotreating catalysts with different active metal microzone distributions were prepared and characterized using XPS,HRTEM,and other methods.The hydrogenation reaction performance of the catalysts was investigated on a micro reactor.The experimental results show that for oxidized catalyst,with the increase of calcination temperature,the dispersion of metal Mo gradually increases,and the dispersion of metal Ni gradually decreases.For sulfurized catalyst,the proportion of Mo^(4+)formed on the prepared catalyst first increases and then decreases,while the sulfurization degree of Ni species gradually decreases.In addition,the average stacking layers of MoS_(2) active phase first increases and then decreases,while the average crystal length first decreases and then increases.When the calcination temperature is 550-650℃,the average stacking layers of the sulfurized catalyst are 3.5-3.7,and the average crystal length is 3.6-3.8 nm.When the calcination temperature is 650℃,the relative aromatics saturation capacity of the catalyst for hydrogenation increases by 4.1 percentage points,and the content of alkanes and total cycloalkane increases.