The deactivation of Pt/KL catalyst during n-heptane aromatization reaction was investigated. The activity fell quickly, especially in the initial stage. The fresh, the used and the regenerated catalysts were characterized by N₂ physisorption, HADDF-STEM, TGA, UV-Raman, etc. The rapid deactivation is attributed to declined accessibility to Pt active sites because of coke deposition. GC-MS analysis revealed that the coke species are polycyclic aromatic hydrocarbons (PAHs). The dimensions of coke molecules and the coke volumes of used catalysts were estimated via DFT calculations. The variation of the contents of different coke species with reaction time implies a shape-selective transformation under micropore constraints. This, together with the XPS-determined depth profile of the coke in the used catalyst, indicates most of the coke was internally encased near the micropore openings. Quantitative evaluation concerning the influence of coke deposition on micropore volume confirms severe channel blockage by coke.

研究了正庚烷芳构化反应过程中Pt / KL催化剂的失活。活动迅速下降，尤其是在初期。新鲜的，使用的和再生的催化剂的特征在于N _2。物理吸附，HADDF-STEM，TGA，UV拉曼等。快速失活归因于由于焦炭沉积导致对Pt活性位点的可及性下降。GC-MS分析表明，焦炭是多环芳烃（PAHs）。焦炭分子的尺寸和所用催化剂的焦炭体积通过DFT计算来估算。不同焦炭种类的含量随反应时间的变化暗示了在微孔约束下的形状选择性转变。这与XPS确定的用过的催化剂中焦炭的深度曲线一起表明，大部分焦炭被内部包裹在微孔开口附近。关于焦炭沉积对微孔体积影响的定量评估证实了焦炭严重堵塞了通道。