Metal–Organic Framework Supported Single Site Chromium(III) Catalyst for Ethylene Oligomerization at Low Pressure and Temperature

Journal Article · Wed Dec 26 00:00:00 EST 2018 · ACS Sustainable Chemistry & Engineering

DOI:https://doi.org/10.1021/acssuschemeng.8b05524· OSTI ID:1566585

Goetjen, Timothy A.  ^[1]; Zhang, Xuan  ^[1]; Liu, Jian  ^[1]; Hupp, Joseph T.  ^[1]; Farha, Omar K.  ^[1]

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1. Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States

A chemically and thermally stable, mesoporous, crystalline metal–organic framework, NU-1000, serves as a structurally well-defined support for catalytic reactions. Depositing chromium(III), a metal widely used in homogeneous ethylene oligomerization catalysts, onto the Zr6 node of NU-1000 allows for the atomically precise determination of the structure of the Cr3+ catalyst through single-crystal X-ray diffraction studies. Chromium modification of NU-1000 was accomplished via solvothermal deposition in MOFs (SIM); termed Cr-SIM-NU-1000, the elaborated material features individual Cr atoms directed in single-site fashion into the mesopore of NU-1000. It was found that NU-1000 serves to stabilize the catalyst against both the typical chemical deactivation of homogeneous systems and leaching from heterogeneous systems. Cr-SIM-NU-1000 exhibits superior catalytic activity, as compared to Cr2O3, for ethylene oligomerization, with 20% conversion at a turnover frequency of about 60 h–1 and products ranging from C8–C28. Given that this catalysis occurs at low temperature (ambient) and low pressure (1 bar C2H4), along with minimal quantity of cocatalyst, the high activity shown by Cr-SIM-NU-1000 enables significant reduction in materials usage and waste. Postcatalytic characterization reveals Cr-SIM-NU-1000 remains intact with no leaching under the reaction conditions.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Energy Frontier Research Center for Inorganometallic Catalyst Design (ICDC); Northwestern Univ., Evanston, IL (United States); Univ. of Minnesota, Minneapolis, MN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC0001329; SC0012702
• OSTI ID: 1566585
• Journal Information: ACS Sustainable Chemistry & Engineering, Vol. 7, Issue 2; ISSN 2168-0485
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

catalysis (heterogeneous)
materials and chemistry by design
synthesis (novel materials)