Enhanced catalyst performance through compartmentalization exemplified by colloidal L-proline modified microgel catalysts
Fernandes, Marta Sofia
Meyer, Anna Astrid
Anakhov, Mikhail V.
Gumerov, Rustam A.
Potemkin, Igor I.
KAUST DepartmentChemical Science Program
KAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
Online Publication Date2019-10-04
Print Publication Date2020-02
Embargo End Date2021-10-04
Permanent link to this recordhttp://hdl.handle.net/10754/659073
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AbstractExploring and controlling chemical reactions in compartments opens new platforms for designing bioinspired catalysts and energy-autonomous systems. Aqueous polymer networks or hydrogels serve as a perfect model for biological tissues, allowing systematic investigations of chemical transformations in compartments. Herein, we report the synthesis of a versatile, colloidal microgel catalyst containing covalently bound L-proline as an organocatalyst. The key finding of our work is that the catalytic activity can be tuned by adjusting the distribution of the organocatalyst in the microgel network as well as the properties of the solvent. We demonstrate that L-proline groups integrated into microgels enable the reaction of 4-nitrobenzaldehyde and cyclohexanone in a heterogeneous reaction mixture in which free L-proline is not active. By controlling the localization of the L-proline groups within the microgel network (core or corona), the rate of the aldol reaction in homogenous and heterogeneous reaction mixtures can be modulated. Furthermore, microgels with covalently attached catalysts can be recycled and reused in sequential catalytic runs without deterioration of the catalyst performance in terms of activity and selectivity. The internal structure of the microgel in heterogeneous reaction mixtures was studied by computer simulations.
CitationKleinschmidt, D., Fernandes, M. S., Mork, M., Meyer, A. A., Krischel, J., Anakhov, M. V., … Pich, A. (2020). Enhanced catalyst performance through compartmentalization exemplified by colloidal l-proline modified microgel catalysts. Journal of Colloid and Interface Science, 559, 76–87. doi:10.1016/j.jcis.2019.10.005
SponsorsThe authors thank Sonderforschungsbereich SFB 985 “Functional Microgels and Microgel Systems” of DFG Deutsche Forschungsgemeinschaft, Volkswagen Foundation and the Government of Russian Federation within Act 211, Contract No. 02.A03.21.0011 for financial support. Computer simulations were supported by the Russian Science Foundation, project No. 15-13-00124. Additionally, the authors are grateful for the equipment supplied by the Center for Chemical Polymer Technology CPT, which is supported by the EU and the federal state of North Rhine-Westphalia (grant EFRE 30 00 883 02), and for the computing time granted by Lomonosov Moscow State University Supercomputer Center . The authors thank Walter–Georg Tillmann for FTIR measurements, Agnieszka Natalia Ksiazkiewicz for calorimetric measurements, Sabrina Mallmann for STEM images and Jan Bierboms for support on graphics.