Highly Active Heterogeneous Catalyst for Ethylene Dimerization Prepared by Selectively Doping Ni on the Surface of a Zeolitic Imidazolate Framework
Autor: | Zhan Shi, Lirong Zheng, Zhen Cao, Edy Abou-Hamad, Lingkun Meng, Alalouni Mohammed R, Yu Han, Luigi Cavallo, Lingmei Liu, Jianjian Wang, Xinglong Dong, Cailing Chen, Kuo-Wei Huang, Chao Guan, Qingpeng Cheng |
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Rok vydání: | 2021 |
Předmět: |
Ethylene
Chemistry Inorganic chemistry General Chemistry 010402 general chemistry Heterogeneous catalysis 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Isotopic labeling Crystal chemistry.chemical_compound Colloid and Surface Chemistry Density functional theory Selectivity Zeolitic imidazolate framework |
Zdroj: | Journal of the American Chemical Society. 143(18) |
ISSN: | 1520-5126 |
Popis: | The production of 1-butene by ethylene dimerization is an important chemical industrial process currently implemented using homogeneous catalysts. Here, we describe a highly active heterogeneous catalyst (Ni-ZIF-8) for ethylene dimerization, which consists of isolating Ni-active sites selectively located on the crystal surface of a zeolitic imidazolate framework. Ni-ZIF-8 can be easily prepared by a simple one-pot synthesis method in which site-specific anchoring of Ni is achieved spontaneously because of the incompatibility between the d8 electronic configuration of Ni2+ and the three-dimensional framework of ZIF-8. The full exposure and square-planar coordination of the Ni sites accounts for the high catalytic activity of Ni-ZIF-8. It exhibits an average ethylene turnover frequency greater than 1 000 000 h-1 (1-butene selectivity >85%) at 35 °C and 50 bar, far exceeding the activities of previously reported heterogeneous catalysts and many homogeneous catalysts under similar conditions. Moreover, compared to molecular Ni complexes used as homogeneous catalysts for ethylene dimerization, Ni-ZIF-8 has significantly higher stability and shows constant activity during 4 h of continuous reaction. Isotopic labeling experiments indicate that ethylene dimerization over Ni-ZIF-8 follows the Cossee-Arlman mechanism, and detailed characterizations combined with density functional theory calculations rationalize this observed high activity. |
Databáze: | OpenAIRE |
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