摘要
应用静态法测定了四种硫化Mo-Ni催化剂的低温氧吸附量及氧吸附后的原位氢程序升温表面反应,并测定了过程中的ESR信号。获得了氧吸附量与加氢脱氮生成油中含氮量(<20ppm)的线性关系,表明低温氧吸附方法可鉴别活性差别较小的催化剂。氧吸附后的原位H_2-TPSR显示一个谱带,峰顶温度较低的催化剂的加氢脱氮活性较高,因此O_2吸附键的强弱亦与活性有关。经过H_2还原后催化剂的ESR信号与O_2吸附前的一致,说明O_2吸附没有影响催化剂的结构。
Oxygen chemisorption capacities of four sulfided alumina-supported Mo-Ni catalysts were determined by static adsorption method at -78℃.A linear relationship between the low temperature O. chemisorption (LTOC) and residual nitrogen in oil product was observed. It indicates that the LTOC method can be used to distinguish the small difference in hydrodenitrogenation (HDN) catalyst activity. Temperature-programmed surface reaction (TPSR) was used to study the catalyst after O2 chemisorption in 4.8% H2/Ar. Only a peak on the TPSR spectra was observed, the lower the peak temperature, the higher the activity is.It suggests that the strength of O2 chemisovbed bond is also related to /the HDN activity. After hydrogen reduction, the ESR signal of the catalyst chemisorbed with O2 is the same as that before O2 chemisorption, therefore, no structure change takes place caused by O2 chemisorption.
