cs9b03282_si_001.pdf (2.42 MB)
Gas-Phase Ethylene Polymerization by Single-Site Cr Centers in a Metal–Organic Framework
journal contribution
posted on 2020-03-10, 15:18 authored by Hoyoung
D. Park, Robert J. Comito, Zhenwei Wu, Guanghui Zhang, Nathan Ricke, Chenyue Sun, Troy Van Voorhis, Jeffrey T. Miller, Yuriy Román-Leshkov, Mircea DincăWe
report a systematic study on the gas-phase polymerization of
ethylene by a metal–organic framework (MOF) catalyst. Cr3+-exchanged MFU-4l (Cr(III)-MFU-4l, MFU-4l = Zn5Cl4(BTDD)3, H2BTDD = bis(1H-1,2,3,-triazolo[4,5-b],[4′,5′-i])dibenzo[1,4]dioxin))
serves as an exemplary system to demonstrate prereaction treatment
with alkylaluminum species as a simple method to isolate an active
MOF catalyst for liquid-free polymerization of ethylene. AlMe3-treated Cr(III)-MFU-4l subjected to 40 bar
of ethylene exhibits a polymerization activity of 52 000 molEthylene·molCr–1·h–1, an order of magnitude higher than that observed
in a slurry-phase reaction with Cr(III)-MFU-4l and
excess alkylaluminum species. Furthermore, product polyethylene exhibits
a low polydispersity index of 1.36 and a free-flowing granular morphology
favorable for industrial processing, highlighting the advantages conferred
by the single-site MOF catalysts in gas-phase ethylene polymerization.
