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A Facile and Scalable Route to the Preparation of Catalytic Membranes With In-situ Synthesized Supramolecular Dendrimer Particle Hosts for Pt(0) Nanoparticles Using a Low Generation PAMAM Dendrimer (G1-NH_2) as Precursor

Kotte, Madhusudhana Rao and Kuvarega, Alex T. and Talapaneni, Siddulu N. and Cho, Manki and Coskun, Ali and Diallo, Mamadou S. (2018) A Facile and Scalable Route to the Preparation of Catalytic Membranes With In-situ Synthesized Supramolecular Dendrimer Particle Hosts for Pt(0) Nanoparticles Using a Low Generation PAMAM Dendrimer (G1-NH_2) as Precursor. ACS Applied Materials & Interfaces, 10 (39). pp. 33238-33251. ISSN 1944-8244. https://resolver.caltech.edu/CaltechAUTHORS:20180911-082846440

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Abstract

Since the first reports of Cu dendrimer-encapsulated nanoparticles (DENs) published in 1998, the dendrimer-templating method has become the best and most versatile method for preparing ultrafine metallic and bimetallic nanoparticles (1–3 nm) with well-defined compositions, high catalytic activity, and tunable selectivity. However, DENs have remained for the most part model systems with limited prospects for scale up and integration into high-performance and reusable catalytic modules and systems for industrial-scale applications. Here, we describe a facile and scalable route to the preparation of catalytic polyvinylidene fluoride (PVDF) membranes with in situ synthesized supramolecular dendrimer particles (SDPs) that can serve as hosts and containers for Pt(0) nanoparticles (2–3 nm). These new catalytic membranes were prepared using a reactive encapsulation process similar to that utilized to prepare Pt DENs by addition of a reducing agent (sodium borohydride) to aqueous complexes of Pt(II) + G4-OH/G6-OH polyamidoamine (PAMAM) dendrimers. However, the SDPs (2.4 μm average diameter) of our new mixed matrix PVDF–PAMAM membranes were synthesized in the dope dispersion without purification prior to film casting using (i) a low-generation PAMAM dendrimer (G1-NH_2) as particle precursor and (ii) epichlorohydrin, an inexpensive functional reagent, as cross-linker. In addition, the membrane PAMAM particles contain secondary amine groups (∼1.9 mequiv per gram of dry membrane), which are more basic and thus have higher Pt binding affinity than the tertiary amine groups of the G4-OH and G6-OH PAMAM dendrimers. Proof-of-concept experiments show that our new PVDF–PAMAM-G1-Pt/membranes can serve as highly active and reusable catalysts for the hydrogenation of alkenes and alkynes to the corresponding alkanes using (i) H_2 at room temperature and a pressure of 1 bar and (ii) low catalyst loadings of ∼1.4–1.6 mg of Pt. Using cyclohexene as model substrate, we observed near quantitative conversion to cyclohexane (∼98%). The regeneration studies showed that our new Pt/membrane catalysts are stable and can be reused for five consecutive reaction cycles for a total duration of 120 h including 60 h of heating at 100 °C under vacuum for substrate, product, and solvent removal with no detectable loss of cyclohexene hydrogenation activity. The overall results of our study point to a promising, versatile, and scalable path for the integration of catalytic membranes with in situ synthesized SDP hosts for Pt(0) nanoparticles into high-throughput modules and systems for heterogeneous catalytic hydrogenations, an important class of reactions that are widely utilized in industry to produce pharmaceuticals, agrochemicals, and specialty chemicals.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/acsami.8b11351DOIArticle
https://pubs.acs.org/doi/suppl/10.1021/acsami.8b11351PublisherSupporting Information
ORCID:
AuthorORCID
Coskun, Ali0000-0002-4760-1546
Diallo, Mamadou S.0000-0002-2571-1568
Alternate Title:A Facile and Scalable Route to the Preparation of Catalytic Membranes With In-situ Synthesized Supramolecular Dendrimer Particle Hosts for Pt(0) Nanoparticles Using a Low Generation PAMAM Dendrimer (G1-NH2) as Precursor
Additional Information:© 2018 American Chemical Society. Received: July 8, 2018; Accepted: September 10, 2018; Published: September 10, 2018. This research was carried out at the Korea Advanced Institute of Science and Technology (KAIST) and at the California Institute of Technology (Caltech). Funding for KAIST was provided by the National Research Foundation of Korea (NRF) [MEST Grant 2012M1A2A2026588] and the EEWS Center (NT080607C0209721). Funding for Caltech was provided by the National Science Foundation (NSF) [CBET EAGER Award 0948485]. A.T.K. thanks the University of South Africa for financial support. Author Contributions: M.R.K. and A.T.K. contributed equally. M.S.D. conceived the research project and designed the study. M.R.K. prepared and characterized the chelating PVDF membrane substrates with in situ synthesized G1-NH2 PAMAM supramolecular dendrimer particles. A.T.K. and M.C. carried out the Pt(IV) membrane loading studies. A.T.K. prepared and characterized the Pt(0) loaded PVDF–PAMAM-G1 membranes. A.C. designed and supervised the catalytic studies. S.N.T. performed the catalytic experiments. M.S.D. drafted the manuscript with contributions from all authors. The authors declare no competing financial interest.
Funders:
Funding AgencyGrant Number
National Research Foundation of Korea2012M1A2A2026588
Korea Advanced Institute of Science and Technology (KAIST)NT080607C0209721
NSFCBET-0948485
University of South AfricaUNSPECIFIED
Subject Keywords:catalytic membranes; supramolecular polymer chemistry; mixed matrix membranes, dendrimer encapsulated nanoparticles; heterogeneous catalysis; hydrogenation
Issue or Number:39
Record Number:CaltechAUTHORS:20180911-082846440
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20180911-082846440
Official Citation:A Facile and Scalable Route to the Preparation of Catalytic Membranes with in Situ Synthesized Supramolecular Dendrimer Particle Hosts for Pt(0) Nanoparticles Using a Low-Generation PAMAM Dendrimer (G1-NH2) as Precursor. Madhusudhana Rao Kotte, Alex T. Kuvarega, Siddulu N. Talapaneni, Manki Cho, Ali Coskun, and Mamadou S. Diallo. ACS Applied Materials & Interfaces 2018 10 (39), 33238-33251 DOI: 10.1021/acsami.8b11351
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:89516
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:11 Sep 2018 16:24
Last Modified:03 Oct 2019 20:16

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