SBA-15 as a Support for Nickel-Based Catalysts for Polymerization Reactions

Two mesoporous SBA-15 materials with different morphologies (spherical and fiber-shaped) were synthesized and evaluated as supports for nickel-based catalysts for polymerization reactions. The supports were pretreated with trimethylaluminum (TMA), and the catalyst dibromo-bis(4-amino-2,3,5,6-tetramethylimino)acenaphthene nickel(II) was attached to the supports and activated with TMA or MAO (methylaluminoxane). Characterization showed that the insertion of cetyltrimethylammonium bromide (CTABr) as a cosurfactant led to spherical SBA-15 with a decrease in particle and pore sizes to 4.8 nm compared to 6.5 nm in traditional fiber-shaped SBA-15. The spherical SBA-15 showed thicker walls than the fiber-shaped SBA-15, attributed to the increase in functional groups of the cosurfactant. The different spherical and fiber-shaped morphologies did not show any significant difference in the productivity of polyethylene. The catalyst supported on spherical SBA-15 materials showed 58% productivity compared to its homogeneous analogue using TMA as a cocatalyst.合成了两种具有不同形貌的介孔SBA-15材料（球形与纤维状），并将其作为镍基催化剂载体用于聚合反应研究。将载体经三甲基铝（trimethylaluminum, TMA）预处理后，将二溴-双(4-氨基-2,3,5,6-四甲基亚氨基)苊镍(II)催化剂负载至载体表面，随后分别以TMA或甲基铝氧烷（methylaluminoxane, MAO）进行活化。表征结果显示，以十六烷基三甲基溴化铵（cetyltrimethylammonium bromide, CTABr）作为助表面活性剂合成的球形SBA-15，其粒径与孔径均为4.8 nm，而传统纤维状SBA-15的对应参数为6.5 nm。球形SBA-15的孔壁厚度大于纤维状SBA-15，该差异源于助表面活性剂官能团含量的提升。两种不同形貌的载体对聚乙烯的催化产率并无显著差异；当以TMA作为助催化剂时，负载于球形SBA-15上的催化剂产率仅为其均相对应催化剂的58%。