Heterogenisation of a Carbonylation Catalyst on Dispersible Microporous Polymer Nanoparticles

Abstract

The methanol carbonylation catalyst, cis-[Rh(CO)2I2]–, has been heterogenised within a dispersible microporous polymer support bearing cationic functionality. The microporous polymer has a core-shell structure in which the porous and insoluble core (a cross-linked co-polymer of divinylbenzene and 4-vinylpyridine) is sterically stabilised by long hydrophilic poly(ethylene glycol) chains, allowing a stable nanoparticle dispersion . Incorporation of 4-vinylpyridine as a co-monomer allows post-synthetic modification to generate N-methylpyridinium sites for electrostatic attachment of the anionic rhodium(I) complex. The dispersibility of the polymer-supported catalyst material facilitates the use of in situ transmission IR spectroscopy to obtain kinetic data for the oxidative addition of iodomethane to immobilised cis-[Rh(CO)2I2]– (the rate-limiting step of the carbonylation cycle). The kinetic data followed a double exponential decay, with an initial fast phase having a rate constant k21 that is ~5× greater than k22 for the slow phase (where k22 is similar to the homogeneous system using N-methylpyridinium counter-ions, CH2Cl2, 25 °C). The polymer-supported catalyst was found to be active for carbonylation of MeOH/MeI to give methyl acetate, with an initial rate ca. double that of the homogeneous analogue under the same conditions (10 bar CO, MeI/MeOH, 120 °C). Activity is lost over longer periods due to leaching of Rh from the support.

Publication DOI: https://doi.org/10.1039/D1CY01989A
Divisions: College of Engineering & Physical Sciences
College of Engineering & Physical Sciences > School of Infrastructure and Sustainable Engineering > Chemical Engineering & Applied Chemistry
College of Engineering & Physical Sciences > Aston Institute of Materials Research (AIMR)
College of Engineering & Physical Sciences > Aston Polymer Research Group
Additional Information: This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Publication ISSN: 2044-4761
Last Modified: 12 Jun 2024 07:23
Date Deposited: 15 Dec 2021 15:19
Full Text Link:
Related URLs: https://pubs.rs ... 2/CY/D1CY01989A (Publisher URL)
PURE Output Type: Article
Published Date: 2021-12-14
Published Online Date: 2021-12-14
Accepted Date: 2021-12-11
Authors: Ivko, Samuel
James, Alex M.
Derry, Matthew (ORCID Profile 0000-0001-5010-6725)
Dawson, Robert
Haynes, Anthony

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License: Creative Commons Attribution

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