Stabilized Vanadium Catalyst for Olefin Polymerization by Site Isolation in a Metal–Organic Framework
Abstract
Vanadium catalysts offer unique selectivity in olefin polymerization, yet are underutilized industrially owing to their poor stability and productivity. Reported here is the immobilization of vanadium by cation exchange in MFU-4l, thus providing a metal-organic framework (MOF) with vanadium in a molecule-like coordination environment. This material forms a single-site heterogeneous catalyst with methylaluminoxane and provides polyethylene with low polydispersity (PDI≈3) and the highest activity (up to 148 000 h-1 ) reported for a MOF-based polymerization catalyst. Furthermore, polyethylene is obtained as a free-flowing powder as desired industrially. Finally, the catalyst shows good structural integrity and retains polymerization activity for over 24 hours, both promising attributes for the commercialization of vanadium-based polyolefins.
This research was supported through a CAREER grant from the National Science Foundation to MD (DMR‐1452612). Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under contract no. DE‐AC02‐06CH11357. MRCAT operations, beamline 10‐BM, are supported by the Department of Energy and the MRCAT member institutions. Z.W., G.Z., and J.T.M. were supported as part of the National Science Foundation Energy Research Center for Innovative and Strategic Transformation of Alkane Resources (CISTAR) under the Cooperative Agreement No. EEC‐1647722.
