镍卟啉加氢反应和扩散行为

采用固定床加氢微型反应装置对八乙基镍卟啉(Ni-OEP)和四苯基镍卟啉(Ni-TPP)进行加氢实验，结合Orbitrap质谱获得了其二氢和四氢中间产物的结构信息，从而丰富了对镍卟啉加氢脱金属连续加氢反应历程的认识。基于反应动力学数据，发现Ni-OEP和Ni-TPP的表观与本征加氢反应均遵循拟一级动力学规律，催化剂NiMo/γ-Al₂O₃相对于NiMo/Zr-SBA-15表现出更高的加氢活性。尽管NiMo/γ-Al₂O₃催化剂具有较大的平均孔径，但无规则的孔道结构显著降低了镍卟啉的扩散系数，导致扩散对加氢脱镍(HDNi)反应的影响更加显著。因此，针对重油中与Ni-OEP和Ni-TPP结构相近的化合物，需要改善工业NiMo/γ-Al₂O₃基催化剂的贯穿性或者提高催化剂孔径，通过强化内扩散传质以实现其高效加氢转化。

Hydrogenation Reaction and Diffusion Behavior of Nickel-Porphyrins

 The hydrogenation experiment was carried out on nickel octaethylporphyrin (Ni-OEP) and nickel tetraphenylporphyrin (Ni-TPP) using a fixed bed micro reaction system for hydrogenation, and on this basis, the structural information of dihydrogen and tetrahydrogen intermediates were further obtained by Orbitrap mass spectrometry, thus enriching the understanding of the continuous hydrogenation reaction process of nickel-porphyrin during hydrodemetallization. Based on the data of reaction kinetics, it has been found that both apparent and intrinsic hydrogenation reactions of Ni-OEP and Ni-TPP are in line with the law of first-order kinetics, and the catalyst NiMo/γ-Al₂O₃ presents a higher hydrogenation activity than NiMo/Zr-SBA-15. Although the catalyst NiMo/γ-Al₂O₃ has a large average pore size, the irregular channel structure can significantly reduce the diffusion coefficient of nickel-porphyrin, as a result of which diffusion has a more significant effect on hydrogenation de-nickel (HDNi) reaction. Therefore, in view of the compounds in heavy oil with similar structures to Ni-OEP and Ni-TPP, it is necessary to improve the penetration of the industrial NiMo/γ-Al₂O₃-based catalyst or increase the pore size of the catalyst, so as to achieve efficient hydrogenation conversion by enhancing the mass transfer via internal diffusion.