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Search for "polymer" in Full Text gives 597 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Degenerative xanthate transfer to olefins under visible-light photocatalysis

  • Atsushi Kaga,
  • Xiangyang Wu,
  • Joel Yi Jie Lim,
  • Hirohito Hayashi,
  • Yunpeng Lu,
  • Edwin K. L. Yeow and
  • Shunsuke Chiba

Beilstein J. Org. Chem. 2018, 14, 3047–3058, doi:10.3762/bjoc.14.283

Graphical Abstract
  • functionalities [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. This concept has also been of particular importance in the field of polymer science, known as reversible addition–fragmentation chain transfer (RAFT) polymerization [15][16]. Mechanistically, the degenerative transfer of xanthates 1 to olefins 2
  • absorption [28][29][30][31][32][33][34][35][36][37]. In the area of polymer synthesis, visible-light-induced RAFT polymerization of xanthates with vinyl monomers under blue LED (light-emitting diode) irradiation has been reported [38][39][40][41]. Visible-light-induced single unit monomer insertion of the
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Published 13 Dec 2018

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

  • Aude-Héloise Bonardi,
  • Frédéric Dumur,
  • Guillaume Noirbent,
  • Jacques Lalevée and
  • Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

Graphical Abstract
  • progresses achieved in terms of synthetic procedures allow now the access to polymers of well-defined composition, molecular weight and architecture. Thanks to these recent progresses in polymer engineering, the scope of applications of polymers is far wider than that of any other class of material, ranging
  • from adhesives, coatings, packaging materials, inks, paints, optics, 3D printing, microelectronics or textiles. From a synthetic viewpoint, photoredox catalysis, originally developed for organic chemistry, has recently been applied to the polymer synthesis, constituting a major breakthrough in polymer
  • regenerates the catalyst. As it is a fast-growing field, this review will be mainly focused on an overview of the recent advances concerning the development of organic and organometallic photoredox catalysts for the photoreticulation of multifunctional monomers for a rapid and efficient access to 3D polymer
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Published 12 Dec 2018

A tutorial review of stereoretentive olefin metathesis based on ruthenium dithiolate catalysts

  • Daniel S. Müller,
  • Olivier Baslé and
  • Marc Mauduit

Beilstein J. Org. Chem. 2018, 14, 2999–3010, doi:10.3762/bjoc.14.279

Graphical Abstract
  • norbornadiene was also investigated by Hoveyda [16]. A highly syndiotactic polymer was obtained by fine tuning of the steric and electronic characteristics of the catalyst (not depicted in this review) [16]. ROCM reactions of norbornene (1) with styrene (5) could be carried out with only one mole percent of
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Published 07 Dec 2018

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

  • Daniel F. Sauer,
  • Johannes Schiffels,
  • Takashi Hayashi,
  • Ulrich Schwaneberg and
  • Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

Graphical Abstract
  • , and Ru [1]. Initially, these complexes were considered to be sensitive towards air and moisture. Nevertheless, adding Ru, Os and Ir salts to an aqueous solution or emulsion of a norbornene derivative led to ring-opening metathesis polymerization to give the corresponding polymer [5][6]. Through
  • , entries 3–5). Again, Ru-6 (longest spacer) was most effective among the catalysts, and up to 78% conversion (corresponds to a TON = 9700; Table 1, entry 5) were achieved with the corresponding Ru-6@NB11 [56]. The corresponding polymer had a molecular weight of Mn = 180,000 g/mol and a narrow molecular
  • the catalyst Ru-4 with the short linker, the activity of Ru-4@NB4exp dropped to TON = 3,000, even though the conjugation was almost quantitative [62]. However, this “influence” on the activity could not be transferred to the regio- and stereoselectivity of the polymer microstructure. Apart from ROMP
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Published 19 Nov 2018

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

  • Yo Hiranoi and
  • Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

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  • Yo Hiranoi Koji Nakano Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan 10.3762/bjoc.14.255 Abstract The alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a highly diverse
  • monomer conversion. A variety of lactones and cyclic diesters, such as ε-caprolactone, β-propiolactone, lactic acid (LA), and glycolide have been used for the ROP. However, the employable monomers are rather limited, which restricts the range of polymer properties. In view of the aforementioned, the
  • alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a promising alternative for polyester synthesis [11][12]. A broad range of epoxides and CAs are readily available and can be copolymerized through this method. Therefore, the polymer architectures and properties can be easily controlled
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Published 05 Nov 2018
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  • sulfonated polymer-carbon nanotubes composites (CNT-P-SO3H) 100–102 were described as outstanding catalysts for liquid phase transesterification of triglycerides 103 with methanol. The catalysts were also used for the esterification of oleic acid (106) with methanol. The important feature of this study is
  • 1 h [67]. The hypercrosslinked supermicroporous polymer (HMP-1, 113) was also designed and prepared by iron(III) chloride catalyzed Friedel–Crafts alkylation of carbazole (111) with α,α′-dibromo-p-xylene (112). In the next step, HMP-1 (113) was sulfonated by Cl-SO3H to form HMP-1-SO3H material 114
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Published 01 Nov 2018

Selective formation of a zwitterion adduct and bicarbonate salt in the efficient CO2 fixation by N-benzyl cyclic guanidine under dry and wet conditions

  • Yoshiaki Yoshida,
  • Naoto Aoyagi and
  • Takeshi Endo

Beilstein J. Org. Chem. 2018, 14, 2204–2211, doi:10.3762/bjoc.14.194

Graphical Abstract
  • only in the field of organic and catalyst chemistry but also in inorganic and polymer chemistry. Especially the adsorbent and the catalyst for CO2 fixation are of interest [1][2][3][4][5]. In particular, the inorganic, organic–inorganic hybrid, dendrimeric catalysts have been developed for chemical
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Published 23 Aug 2018

Synergistic electrodeposition of bilayer films and analysis by Raman spectroscopy

  • Saadeldin E. T. Elmasly,
  • Luca Guerrini,
  • Joseph Cameron,
  • Alexander L. Kanibolotsky,
  • Neil J. Findlay,
  • Karen Faulds and
  • Peter J. Skabara

Beilstein J. Org. Chem. 2018, 14, 2186–2189, doi:10.3762/bjoc.14.191

Graphical Abstract
  • Glasgow, University Place, Glasgow, G12 8QQ, UK Institute of Physical-Organic Chemistry and Coal Chemistry, 02160 Kyiv, Ukraine 10.3762/bjoc.14.191 Abstract A novel methodology towards fabrication of multilayer organic devices, employing electrochemical polymer growth to form PEDOT and PEDTT layers, is
  • successfully demonstrated. Moreover, careful control of the electrochemical conditions allows the degree of doping to be effectively altered for one of the polymer layers. Raman spectroscopy confirmed the formation and doped states of the PEDOT/PEDTT bilayer. The electrochemical deposition of a bilayer
  • containing a de-doped PEDTT layer on top of doped PEDOT is analogous to a solution-processed organic semiconductor layer deposited on top of a PEDOT:PSS layer without the acidic PSS polymer. However, the poor solubility of electrochemically deposited PEDTT (or other electropolymerised potential candidates
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Published 21 Aug 2018

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

  • Vladimir A. Burilov,
  • Guzaliya A. Fatikhova,
  • Mariya N. Dokuchaeva,
  • Ramil I. Nugmanov,
  • Diana A. Mironova,
  • Pavel V. Dorovatovskii,
  • Victor N. Khrustalev,
  • Svetlana E. Solovieva and
  • Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

Graphical Abstract
  • peak at 674 nm, corresponding to the blue form of the polymer, reached its maximum after 15 minutes of irradiation. It was found that the calixarene 10b itself acted as stabilizer for AEPCDA vesicles: a hyperchromic effect upon the addition of calixarene up to 50 mol % was observed (Figure 6). This
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Published 31 Jul 2018

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

  • Mohammad A. Alnajjar,
  • Jürgen Bartelmeß,
  • Robert Hein,
  • Pichandi Ashokkumar,
  • Mohamed Nilam,
  • Werner M. Nau,
  • Knut Rurack and
  • Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

Graphical Abstract
  • used polymer microparticles with surface-bound CB7 [66] and added them to a solution containing a mixture of 5 and 1-(aminomethyl)adamantane (AMADA). The latter was added to reduce the surface group density of the dye and prevent undesired self-quenching at high surface concentrations of the
  • fluorophore. After centrifugation and washing of the polymer particles, surface-bound 5 could be clearly visualized by fluorescence microscopy on CB7-functionalized polymer particles, whereas polymer particles lacking CB7 on the surface did not show any fluorescence (Figure 7). This result is consistent with
  • 77.9 µs, respectively. Fluorescence microscopy images of 1 mg/mL polymer microspheres a) with or b) without surface-bound CB7 after incubation with 10 nM 5 and 1 µM AMADA in 10 mM citrate, pH 3.3 (30% (v/v) ACN in water) and centrifugation to immobilize 5 through supramolecular host–guest binding
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Published 30 Jul 2018

An amphiphilic pseudo[1]catenane: neutral guest-induced clouding point change

  • Tomoki Ogoshi,
  • Tomohiro Akutsu and
  • Tada-aki Yamagishi

Beilstein J. Org. Chem. 2018, 14, 1937–1943, doi:10.3762/bjoc.14.167

Graphical Abstract
  • ; Introduction Thermo-responsive molecules exhibiting a lower critical solution temperature (LCST) are very important for applications such as controlled drug release [1], molecular separation [2], and tissue culture substrates [3]. Poly(N-isopropylacrylamide) (pNIPAAm) is a widely used thermo-responsive polymer
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Published 26 Jul 2018

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

  • Mrityunjay K. Sharma,
  • Roopashri B. Acharya,
  • Chinmay A. Shukla and
  • Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

Graphical Abstract
  • where it is mixed with the nitroalkane stream. The reaction stream can then be passed through reactor R6 which is packed with polymer-supported (S)-pybox–calcium chloride and maintained at 0 °C. The reaction stream can be further passed to intermediate tank T6 where it can be preheated to 100 °C. The
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Published 26 Jul 2018

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

  • Fateh V. Singh,
  • Priyanka B. Kole,
  • Saeesh R. Mangaonkar and
  • Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

Graphical Abstract
  • acid and 4-iodophenylacetic acid in two steps (Figure 2). Both polymer-supported reagents 17a and 17b were used in similar spirocyclizations of tyrosine 14. Both tyrosine 14a and N-protected tyrosine derivatives 14b,c were used as starting material and results of their spirolactonization are summarized
  • derivatives 14b and 14c (Table 1, entries 3–6). The advantage of this reaction is that the polymer-supported reagent can be regenerated and reused without loss of any significant activity [69]. In 2010, Kita and co-workers [70] developed another approach for PIDA-mediated spirolactonization of 1-(p
  • , para-substituted phenol 131 was cyclized to spirodienone 133 using polymer supported (diacetoxy)iodobenzene reagent 132 (Scheme 49). The desired product 133 was obtained in 70% yield without conventional work-up procedure and purification by chromatographic technique. Furthermore, synthesized
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Published 17 Jul 2018

β-Hydroxy sulfides and their syntheses

  • Mokgethwa B. Marakalala,
  • Edwin M. Mmutlane and
  • Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

Graphical Abstract
  • -radical mediated “click” process with diverse applications in small molecule and polymer synthesis and has been reviewed [74][75][76]. The importance of the thiol-ene reaction in the synthesis of β-hydroxy sulfides is exemplified by the work of Scanlan and co-workers as shown in Scheme 41 [77][78
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Published 05 Jul 2018

Synthesis of diamido-bridged bis-pillar[5]arenes and tris-pillar[5]arenes for construction of unique [1]rotaxanes and bis-[1]rotaxanes

  • Ying Han,
  • Li-Ming Xu,
  • Cui-Yun Nie,
  • Shuo Jiang,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2018, 14, 1660–1667, doi:10.3762/bjoc.14.142

Graphical Abstract
  • polymer. This result is consistent to the Cao’s previously reported results in the series of pillar[5]arenes bearing aliphatic esters [49], in that they found the chain of methyl oxybutyrate did not threaded into the cavity of pillar[5]arene. The above synthetic pillar[5]arene mono(oxyalkoxy)benzoic acids
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Published 04 Jul 2018

Direct electrochemical generation of organic carbonates by dehydrogenative coupling

  • Tile Gieshoff,
  • Vinh Trieu,
  • Jan Heijl and
  • Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2018, 14, 1578–1582, doi:10.3762/bjoc.14.135

Graphical Abstract
  • polymer formation with less reactive epoxides (other than ethylene oxide) [7][8][9][10]. Electrochemistry has the capability to access products by extraordinary reaction pathways. Electric current is an inexpensive reagent and inherently safe reaction set-ups ensure a resource saving and applicable
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Published 27 Jun 2018

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

  • Alberto Spinella,
  • Marco Russo,
  • Antonella Di Vincenzo,
  • Delia Chillura Martino and
  • Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

Graphical Abstract
  • efficiency indeed depends on the effective occurrence of both electrostatic and hydrophobic interactions between the guest and the polymer lattice. Thus, our CaNS nanosponges can be considered as a new class of purely synthetic smart absorbent materials. Keywords: calixarenes; nanosponges; smart materials
  • composites loaded with quercetin may show improved cytotoxic activity towards some human breast cancer cell lines [32], likely due to a synergistic action between the polyphenol nutraceutic guest molecule and triazole derivatives coming from the progressive disgregation of the co-polymer carrier. From the
  • number of azido groups present in the molecule. The actual accomplishment of the CuAAC reaction, and therefore the formation of the reticulated polymer network, was first assessed by means of FTIR spectroscopy. The FTIR spectra of the propargyloxycalixarene precursor Ca-OP, of the diazide A2 and the
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Published 20 Jun 2018

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

  • Cristina Cebrián and
  • Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

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Published 18 Jun 2018

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

  • Jonas Weidner,
  • Stefan Barwe,
  • Kirill Sliozberg,
  • Stefan Piontek,
  • Justus Masa,
  • Ulf-Peter Apfel and
  • Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

Graphical Abstract
  • hence leads to an overall improved energy efficiency for H2 production. In addition, contrary to the “waste product O2”, FDCA can be further utilized, e.g., for production of polyethylene 2,5-furandicarboxylate (PEF), a sustainable polymer analog to polyethylene terephthalate (PET) and thus represents a
  • -refinery based chemicals for a “green” chemical industry [6][7][8]. FDCA was suggested to replace, e.g., terephthalic acid as building block for the formation of polyamides, polyesters, and polyurethanes [6]. Especially, the polymer polyethylene terephthalate (PET), a perpetually used polymer, could be
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Published 13 Jun 2018

Atom-economical group-transfer reactions with hypervalent iodine compounds

  • Andreas Boelke,
  • Peter Finkbeiner and
  • Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

Graphical Abstract
  • this “green” reaction parameter. To overcome this obstacle, promising approaches are the use of iodoarenes as precatalysts in combination with external co-oxidants and the utilization of specific hypervalent iodine compounds (polymer-supported as well as non-polymeric species), whose reduced forms are
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Published 30 May 2018

Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes

  • Zhensheng Zhao and
  • Graham K. Murphy

Beilstein J. Org. Chem. 2018, 14, 796–802, doi:10.3762/bjoc.14.67

Graphical Abstract
  • . Experimental evidence suggests that a radical mechanism is involved. Keywords: allene; chlorination; hypervalent iodine; synthetic methods; vinyl chloride; Introduction Organochlorine compounds are vital as polymer precursors [1], as pharmaceuticals [2][3] and agrochemicals [4][5][6] and as functional
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Published 09 Apr 2018

Nanoreactors for green catalysis

  • M. Teresa De Martino,
  • Loai K. E. A. Abdelmohsen,
  • Floris P. J. T. Rutjes and
  • Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

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  • , namely: (polymer) vesicles, micelles, dendrimers and nanogels. The ability and efficiency of catalytic nanoreactors to carry out organic reactions in water, to perform cascade reaction and their ability to be recycled will be discussed. Keywords: catalysis; dendrimers; green chemistry; nanogels
  • Pd catalyst together with a PAA (poly(acrylic acid)) based polymer self-assembled in water [32]. The catalytic activity of the nanostructures was compared to the results achieved with the small molecule analogues of the pincer Pd complex, in a Suzuki–Miyaura coupling. When the reaction of vinyl
  • -polyisocyanopeptide (PS-PIAT) and CalB was incorporated within either the lumen or polymer membrane (Figure 5). ROP is usually performed in organic solvent so that hydrolysis reactions can be avoided [17]. However, when nanoreactors were used, polymerization proceeded efficiently in water and without formation of any
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Published 29 Mar 2018

Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions

  • Kendra Leahy Denlinger,
  • Lianna Ortiz-Trankina,
  • Preston Carr,
  • Kingsley Benson,
  • Daniel C. Waddell and
  • James Mack

Beilstein J. Org. Chem. 2018, 14, 688–696, doi:10.3762/bjoc.14.57

Graphical Abstract
  • a vast amount of intrigue by the chemical community [24][25][26]. Our research group has continued the study of the Wittig reaction under mechanochemical conditions with the use of a functionalized polymer resin. During these studies, we discovered a few exciting differences between our results and
  • . Results and Discussion Liquid-assisted grinding To focus the study, benzaldehyde, benzyl bromide, polymer-supported triphenylphosphine (PS-C6H4-PPh2) and potassium carbonate were ball-milled in a stainless steel vial with two LAG solvents at opposite ends of the dielectric spectrum, as well as a control
  • that Cs+ and Br− would be a good pair, since their values are similar. We would expect Rb+ to pair well with Br− for the same reason. To test this idea and to understand the effect of the interaction, we conducted the solvent-free polymer-supported Wittig reaction with various carbonate salts and alkyl
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Published 23 Mar 2018

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

  • Lin Gan,
  • Xianglong Li,
  • Xinyi Cai,
  • Kunkun Liu,
  • Wei Li and
  • Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

Graphical Abstract
  • Lin Gan Xianglong Li Xinyi Cai Kunkun Liu Wei Li Shi-Jian Su State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Tianhe District, Guangzhou 510640, Guangdong Province, P. R
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Published 22 Mar 2018

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

  • Cristina Mozo Mulero,
  • Alfonso Sáez,
  • Jesús Iniesta and
  • Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

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  • a polymer electrolyte membrane electrochemical reactor (PEMER). Palladium (Pd) nanoparticles were synthesised and supported on a carbonaceous matrix (Pd/C) with a 28 wt % of Pd with respect to carbon material. Pd/C was characterised by transmission electron microscopy (TEM), and thermogravimetric
  • analysis (TGA). Cathodes were prepared using Pd electrocatalytic loadings (LPd) of 0.2 and 0.02 mg cm−2. The anode consisted of hydrogen gas diffusion for the electrooxidation of hydrogen gas, and a 117 Nafion exchange membrane acted as a cationic polymer electrolyte membrane. Benzophenone solution was
  • ; electrocatalytic hydrogenation; palladium nanoparticles; polymer electrolyte membrane; Introduction Hydrogenation is a common procedure applied in organic chemistry industry based on the use of an external hydrogen source, generally carried out under moderate experimental conditions of high temperature (until 673
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Published 01 Mar 2018
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