摘要
将某一时刻催化剂表面上活性中心数目与初始时刻活性中心数目之比定义为催化剂表观活性因子,并认为此活性因子包含在主催化反应速率系数的指前因子中。考虑活性中心在催化剂表面分布的不均匀性,在现有级数型失活动力学模型基础上,经推导得到表观活性因子的具体表达式及其极限式,该式在一般情况下为不可分。最后,结合之前报道的具有较高普适性的反应转化率方程式,得到催化反应转化率与运转时间的关系方程,并以Ni-B/SiO2催化剂在噻吩存在下芳烃加氢反应为例加以验证。结果表明,所提出的失活动力学表达式可以较好地描述镍基催化剂硫中毒的行为,方程参量具有物理意义,方程可以较精确地拟合实验数据。
Based on the current power-kinetic model for catalyst deactivation,the apparent activity factor usually in a non-separable form was derived by taking the non-uniform distribution of catalyst active sites into account.Combined with the relatively comprehensive conversion relationship reported previously,a model correlating conversion with reaction time was proposed.Its validity was verified by fitting experimental data from ethylbenzene hydrogenation with Ni-B/SiO2 catalyst in the presence of thiophene.The results showed that the model with predictive capability could describe the nickel catalyst deactivation behavior,and the model parameters were endowed with physical meaning.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2012年第10期3131-3137,共7页
CIESC Journal
基金
国家重点基础研究发展计划项目(2010CB226903)
国家自然科学基金项目(21073147
20973140)~~
关键词
中毒
失活
反应动力学
芳烃加氢
燃料油
poisoning
deactivation
reaction kinetics
aromatics hydrogenation
fuel oil
