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Marelli M, Perez Schmidt P, Nguyen XT, Pitzalis E, Poggini L, Ragona L, Pagano K, Aronica LA, Polito L, Evangelisti C. Photo-induced microfluidic production of ultrasmall platinum nanoparticles. NANOSCALE 2024. [PMID: 39385674 DOI: 10.1039/d4nr02971b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
We describe here the synthesis of ultrasmall Pt nanoparticles (NPs) obtained by a robust and reliable protocol using UV-Vis photoreduction of a platinum salt precursor, under continuous flow conditions. These ligand-free Pt NPs were rapidly dispersed onto a solid support or stabilized towards aggregation as a colloidal solution by the addition of an appropriate ligand in the reaction mixture. The proposed protocol exploits a microfluidic platform where the Pt4+ precursor is photo-reduced to small Pt0 NPs (1.3 nm) at room temperature in the presence of ethanol, without any additional reducing agent. We apply the protocol to prepare Pt NPs highly dispersed on carbon support (Pt/C) proven to be a very efficient heterogeneous catalyst for both the hydrosilylation of terminal alkynes and hydrogenation of nitroaromatic compounds, selected as model reactions. Furthermore, we exploit the versatility of this microfluidic approach to produce stabilized aqueous/ethanol colloidal solutions of Pt NPs, employing a ligand of choice (e.g., PVP or a thiol-ligand). These colloids offer long-term storage and further ligand modification. We showcase the synthesis of biocompatible glycol-stabilized Pt nanoparticles as an exemplary application.
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Affiliation(s)
- Marcello Marelli
- CNR-SCITEC, Institute of Science and Chemical Technologies "Giulio Natta", Via Fantoli 16/15, 20138 Milano, Italy.
| | - Patricia Perez Schmidt
- CNR-SCITEC, Institute of Science and Chemical Technologies "Giulio Natta", Via Fantoli 16/15, 20138 Milano, Italy.
| | - Xuan Trung Nguyen
- CNR-ICCOM, Institute of Chemistry of OrganoMetallic Compounds, Via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Emanuela Pitzalis
- CNR-ICCOM, Institute of Chemistry of OrganoMetallic Compounds, Via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Lorenzo Poggini
- CNR-ICCOM, Institute of Chemistry of OrganoMetallic Compounds, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
- Department of Chemistry "U. Schiff" - DICUS - and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, FI, Italy
| | - Laura Ragona
- CNR-SCITEC, Institute of Science and Chemical Technologies "Giulio Natta", Via Corti 12, 20133 Milano, Italy
| | - Katiuscia Pagano
- CNR-SCITEC, Institute of Science and Chemical Technologies "Giulio Natta", Via Corti 12, 20133 Milano, Italy
| | - Laura Antonella Aronica
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Laura Polito
- CNR-SCITEC, Institute of Science and Chemical Technologies "Giulio Natta", Via Fantoli 16/15, 20138 Milano, Italy.
| | - Claudio Evangelisti
- CNR-ICCOM, Institute of Chemistry of OrganoMetallic Compounds, Via G. Moruzzi 1, 56124 Pisa, Italy.
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2
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Rubio-Ruiz B, Pérez-López AM, Uson L, Ortega-Liebana MC, Valero T, Arruebo M, Hueso JL, Sebastian V, Santamaria J, Unciti-Broceta A. In Cellulo Bioorthogonal Catalysis by Encapsulated AuPd Nanoalloys: Overcoming Intracellular Deactivation. NANO LETTERS 2023; 23:804-811. [PMID: 36648322 PMCID: PMC9912372 DOI: 10.1021/acs.nanolett.2c03593] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/09/2023] [Indexed: 06/17/2023]
Abstract
Bioorthogonal metallocatalysis has opened up a xenobiotic route to perform nonenzymatic catalytic transformations in living settings. Despite their promising features, most metals are deactivated inside cells by a myriad of reactive biomolecules, including biogenic thiols, thereby limiting the catalytic functioning of these abiotic reagents. Here we report the development of cytocompatible alloyed AuPd nanoparticles with the capacity to elicit bioorthogonal depropargylations with high efficiency in biological media. We also show that the intracellular catalytic performance of these nanoalloys is significantly enhanced by protecting them following two different encapsulation methods. Encapsulation in mesoporous silica nanorods resulted in augmented catalyst reactivity, whereas the use of a biodegradable PLGA matrix increased nanoalloy delivery across the cell membrane. The functional potential of encapsulated AuPd was demonstrated by releasing the potent chemotherapy drug paclitaxel inside cancer cells. Nanoalloy encapsulation provides a novel methodology to develop nanoreactors capable of mediating new-to-life reactions in cells.
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Affiliation(s)
- Belén Rubio-Ruiz
- Edinburgh
Cancer Research, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, U.K.
- Department
of Medicinal and Organic Chemistry and Unit of Excellence in Chemistry
Applied to Biomedicine and Environment, Faculty of Pharmacy, Campus
Cartuja s/n, University of Granada, 18071 Granada, Spain
- GENYO,
Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, Avda. Ilustración 114, 18016 Granada, Spain
| | - Ana M. Pérez-López
- Edinburgh
Cancer Research, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, U.K.
- TU
Berlin, Institut für
Biotechnologie, Aufgang
17-1, Level 4, Raum 472, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Laura Uson
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Department
of Chemical Engineering and Environmental Technologies, University of Zaragoza, 50018 Zaragoza, Spain
| | - M. Carmen Ortega-Liebana
- Edinburgh
Cancer Research, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, U.K.
- Department
of Medicinal and Organic Chemistry and Unit of Excellence in Chemistry
Applied to Biomedicine and Environment, Faculty of Pharmacy, Campus
Cartuja s/n, University of Granada, 18071 Granada, Spain
- GENYO,
Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, Avda. Ilustración 114, 18016 Granada, Spain
| | - Teresa Valero
- Edinburgh
Cancer Research, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, U.K.
- Department
of Medicinal and Organic Chemistry and Unit of Excellence in Chemistry
Applied to Biomedicine and Environment, Faculty of Pharmacy, Campus
Cartuja s/n, University of Granada, 18071 Granada, Spain
- GENYO,
Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, Avda. Ilustración 114, 18016 Granada, Spain
| | - Manuel Arruebo
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Department
of Chemical Engineering and Environmental Technologies, University of Zaragoza, 50018 Zaragoza, Spain
- Networking
Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-
BBN), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jose L. Hueso
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Department
of Chemical Engineering and Environmental Technologies, University of Zaragoza, 50018 Zaragoza, Spain
- Networking
Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-
BBN), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Victor Sebastian
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Department
of Chemical Engineering and Environmental Technologies, University of Zaragoza, 50018 Zaragoza, Spain
- Networking
Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-
BBN), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jesus Santamaria
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Department
of Chemical Engineering and Environmental Technologies, University of Zaragoza, 50018 Zaragoza, Spain
- Networking
Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-
BBN), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Asier Unciti-Broceta
- Edinburgh
Cancer Research, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, U.K.
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3
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Zhao X, Li J, Jian H, Lu M, Wang M. Two Novel Schiff Base Manganese Complexes as Bifunctional Electrocatalysts for CO 2 Reduction and Water Oxidation. Molecules 2023; 28:1074. [PMID: 36770742 PMCID: PMC9920694 DOI: 10.3390/molecules28031074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
One mononuclear Mn(III) complex [MnIIIL(H2O)(MeCN)](ClO4) (1) and one hetero-binuclear complex [(CuIILMnII(H2O)3)(CuIIL)2](ClO4)2·CH3OH (2) have been synthesized with the Schiff base ligand (H2L = N,N'-bis(3-methoxysalicylidene)-1,2-phenylenediamine). Single crystal X-ray structural analysis manifests that the Mn(III) ion in 1 has an octahedral coordination structure, whereas the Mn(II) ion in 2 possesses a trigonal bipyramidal configuration and the Cu(II) ion in 2 is four-coordinated with a square-planar geometry. Electrochimerical catalytic investigation demonstrates that the two complexes can electrochemically catalyze water oxidation and CO2 reduction simultaneously. The coordination environments of the Mn(III), Mn(II), and Cu(II) ions in 1 and 2 were provided by the Schiff base ligand (L) and labile solvent molecules. The coordinately unsaturated environment of the Cu(II) center in 2 can perfectly facilitate the catalytic performance of 2. Complexes 1 and 2 display that the over potentials for water oxidation are 728 mV and 216 mV, faradaic efficiencies (FEs) are 88% and 92%, respectively, as well as the turnover frequency (TOF) values for the catalytic reduction of CO2 to CO are 0.38 s-1 at -1.65 V and 15.97 s-1 at -1.60 V, respectively. Complex 2 shows much better catalytic performance for both water oxidation and CO2 reduction than that of complex 1, which could be owing to a structural reason which is attributed to the synergistic catalytic action of the neighboring Mn(III) and Cu(II) active sites in 2. Complexes 1 and 2 are the first two compounds coordinated with Schiff base ligand for both water oxidation and CO2 reduction. The finding in this work can offer significant inspiration for the future development of electrocatalysis in this area.
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Affiliation(s)
- Xin Zhao
- School of Materials Science and Engineering, Institute for New Energy Materials & Low Carbon Technologies, Tianjin University of Technology, Tianjin 300384, China
| | - Jingjing Li
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China
| | - Hengxin Jian
- School of Materials Science and Engineering, Institute for New Energy Materials & Low Carbon Technologies, Tianjin University of Technology, Tianjin 300384, China
| | - Mengyu Lu
- School of Materials Science and Engineering, Institute for New Energy Materials & Low Carbon Technologies, Tianjin University of Technology, Tianjin 300384, China
| | - Mei Wang
- School of Materials Science and Engineering, Institute for New Energy Materials & Low Carbon Technologies, Tianjin University of Technology, Tianjin 300384, China
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Batch synthesis of high activity and durability carbon supported platinum catalysts for oxygen reduction reaction using a new facile continuous microwave pipeline technology. J Colloid Interface Sci 2022; 628:174-188. [PMID: 35987155 DOI: 10.1016/j.jcis.2022.08.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/07/2022] [Accepted: 08/10/2022] [Indexed: 11/23/2022]
Abstract
Traditional synthesis methodologies for fuel cell catalyst production involve long reactions and uncontrollable reaction processes. Synthesis methods for the production of catalysts typically have difficulties to achieve catalysts materials with consistency, high activity, and durability. In this study, a fast, simple, and suitable continuous pipeline microwave method for catalyst mass production was developed, with the carbon carrier being treated at different temperatures simultaneously. The method herein developed resulted in carbon-supported platinum (Pt) catalysts with high activity and high durability. In addition, the half-wave potential of the catalyst exceeded 0.9 V, the electrochemical active surface area reached 85.7 m2-gPt-1, and the mass specific activity reached 171.1 mA-mg-1. Remarkably, after 30,000 cycles of Pt attenuation tests and 30,000 cycles of carbon carrier attenuation tests, the retention rate of the annealed carbon carrier catalyst reached 80 %. As a membrane electrode, the catalyst generated a single cell maximum power density of 1.4 W-cm-2, and the Pt content reached 0.286 gPt-kW-1. The work provides an effective and practical method for the mass production of high-performance and high-durability catalysts, which guiding significance for mass production of catalysts.
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Sebastian V. Toward continuous production of high-quality nanomaterials using microfluidics: nanoengineering the shape, structure and chemical composition. NANOSCALE 2022; 14:4411-4447. [PMID: 35274121 DOI: 10.1039/d1nr06342a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Over the last decade, a multitude of synthesis strategies has been reported for the production of high-quality nanoparticles. Wet-chemical methods are generally the most efficient synthesis procedures since high control of crystallinity and physicochemical properties can be achieved. However, a number of challenges remain from inadequate reaction control during the nanocrystallization process; specifically variability, selectivity, scalability and safety. These shortcomings complicate the synthesis, make it difficult to obtain a uniform product with desired properties, and present serious limitations for scaling the production of colloidal nanocrystals from academic studies to industrial applications. Continuous flow reactors based on microfluidic principles offer potential solutions and advantages. The reproducibility of reaction conditions in microfluidics and therefore product quality have proved to exceed those obtained by batch processing. Considering that in nanoparticles' production not only is it crucial to control the particle size distribution, but also the shape and chemical composition, this review presents an overview of the current state-of-the-art in synthesis of anisotropic and faceted nanostructures by using microfluidics techniques. The review surveys the available tools that enable shape and chemical control, including secondary growth methods, active segmented flow, and photoinduced shape conversion. In addition, emphasis is placed on the available approaches developed to tune the structure and chemical composition of nanomaterials in order to produce complex heterostructures in a continuous and reproducible fashion.
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Affiliation(s)
- Victor Sebastian
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain.
- Department of Chemical Engineering and Environmental Technologies, University de Zaragoza, 50018, Zaragoza, Spain
- Networking Research Centre of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), C/Monforte de Lemos, 3-5 Pabellón 11, 28029 Madrid, Spain
- Laboratorio de Microscopías Avanzadas, Universidad de Zaragoza, 50018 Zaragoza, Spain
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Castillo-Vallés M, Romero P, Sebastián V, Ros MB. Microfluidics for the rapid and controlled preparation of organic nanotubes of bent-core based dendrimers. NANOSCALE ADVANCES 2021; 3:1682-1689. [PMID: 36132558 PMCID: PMC9418585 DOI: 10.1039/d0na00744g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/05/2021] [Indexed: 06/15/2023]
Abstract
Recently, bent-core molecules have emerged as excellent building blocks for the obtaining of nanostructures in solvents. Herein, we report the use of a coaxial microfluidic system as a promising tool to control the self-assembly of non-conventional bent-core amphiphiles. Moreover, a TEM study to comprehend the hierarchical self-assembly process in solution was carried out. The proposed tool provides both a cost-effective platform to save hard-to-synthesise reagents and a rapid method to screen a plethora of different parameters, i.e., THF/water ratio, residence time, concentration of the amphiphile, temperature and pH. The experiments allowed to test for the first time the suitability of microfluidics for the self-assembly of bent-core molecules, as well as the study of a range of conditions to control the assembly of different nanostructures in a rapid and controlled manner. Additionally, organic nanostructures were combined with gold nanoparticles to prepare nanocomposites with enhanced properties. Both organic and hybrid nanostructures were also obtained in the solid state. These results may inspire scientists working on supramolecular chemistry and bent-core molecules expanding the scope of microfluidic systems for the self-assembly of other low-molecular-weight compounds.
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Affiliation(s)
- Martín Castillo-Vallés
- Department of Organic Chemistry, Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza Zaragoza 50009 Spain
| | - Pilar Romero
- Department of Organic Chemistry, Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza Zaragoza 50009 Spain
| | - Víctor Sebastián
- Department of Chemical Engineering and Environmental Technology, Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza Zaragoza 50009 Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN 28029-Madrid Spain
| | - M Blanca Ros
- Department of Organic Chemistry, Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza Zaragoza 50009 Spain
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Mateo JM, de la Hoz A, Usón L, Arruebo M, Sebastian V, Gomez MV. Insights into the mechanism of the formation of noble metal nanoparticles by in situ NMR spectroscopy. NANOSCALE ADVANCES 2020; 2:3954-3962. [PMID: 36132804 PMCID: PMC9417889 DOI: 10.1039/d0na00159g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/23/2020] [Indexed: 05/09/2023]
Abstract
High-resolution solution Nuclear Magnetic Resonance (NMR) spectroscopy has been used to gain insights into the mechanism of the formation of gold, platinum and gold-platinum alloyed nanoparticles using metal precursors and tetrakis(hydroxymethyl)phosphonium chloride (THPC) as starting materials. THPC is widely used in nanochemistry as a reductant and stabilizer of nanoparticles, however the identity of the species responsible for each role is unknown. The multinuclear study of the reaction media by NMR spectroscopy allowed us to elucidate the structure of all the compounds that participate in the transformation from the metal salt precursor to the reduced metal that forms the nanoparticle, thus clarifying the controversy found in the literature regarding the formation of THPC-based compounds. The progress of the reaction was monitored from the initial moments of the synthesis to the end of the reaction and after long periods of time. Insights into the dual role of THPC were gained, identifying methanol and hydrogen as the actual reducing agents, and tris(hydroxymethyl)phosphine oxide (THPO) as the real stabilizing agent. Finally, the different stabilities of gold and platinum nanoparticles can be attributed to the different catalytic activities of the metals.
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Affiliation(s)
- Jose Miguel Mateo
- Department of Inorganic, Organic and Biochemistry, Faculty of Chemical Sciences and Technologies, Universidad de Castilla-La Mancha (UCLM) Av. Camilo José Cela 10 13071 Ciudad Real Spain
| | - Antonio de la Hoz
- Department of Inorganic, Organic and Biochemistry, Faculty of Chemical Sciences and Technologies, Universidad de Castilla-La Mancha (UCLM) Av. Camilo José Cela 10 13071 Ciudad Real Spain
| | - Laura Usón
- Department of Chemical & Environmental Engineering, Nanoscience Institute of Aragon (INA), Aragón Materials Science Institute, ICMA, University of Zaragoza Mariano Esquillor edif. I+D 50018 Zaragoza Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigación Biomédica en Red C/Monforte de Lemos 3-5, Pabellón 11 28029 Madrid Spain
| | - Manuel Arruebo
- Department of Chemical & Environmental Engineering, Nanoscience Institute of Aragon (INA), Aragón Materials Science Institute, ICMA, University of Zaragoza Mariano Esquillor edif. I+D 50018 Zaragoza Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigación Biomédica en Red C/Monforte de Lemos 3-5, Pabellón 11 28029 Madrid Spain
| | - Victor Sebastian
- Department of Chemical & Environmental Engineering, Nanoscience Institute of Aragon (INA), Aragón Materials Science Institute, ICMA, University of Zaragoza Mariano Esquillor edif. I+D 50018 Zaragoza Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigación Biomédica en Red C/Monforte de Lemos 3-5, Pabellón 11 28029 Madrid Spain
| | - M Victoria Gomez
- Department of Inorganic, Organic and Biochemistry, Faculty of Chemical Sciences and Technologies, Universidad de Castilla-La Mancha (UCLM) Av. Camilo José Cela 10 13071 Ciudad Real Spain
- Regional Institute of Applied Scientific Research (IRICA), Universidad de Castilla-La Mancha (UCLM) Av. Camilo José Cela, sn 13071 Ciudad Real Spain
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He X, Xia Y, Liang C, Zhang J, Huang H, Gan Y, Zhao C, Zhang W. A flexible non-precious metal Fe-N/C catalyst for highly efficient oxygen reduction reaction. NANOTECHNOLOGY 2019; 30:144001. [PMID: 30620932 DOI: 10.1088/1361-6528/aafc7c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A novel, flexible non-precious-metal oxygen reduction reaction catalyst is fabricated by direct pyrolysis of carbon cloth decorated with an iron-coordinated aniline and pyrrole copolymer. The resultant Fe-N/C manifests superior activity, long-term stability in alkaline media and comparable activity in acidic electrolyte. The precursor carbon cloth modified with aniline and pyrrole copolymer provides high densities of carbon, nitrogen and iron-doping sites, which generates a great many active sites. Compared to the Pt/C catalyst, Fe-N/C pyrolyzed at 850 °C (Fe-N/C-850) shows excellent activity with onset and half-wave potentials of 17 mV and -174 mV in 0.1 M KOH, which are more activated than an iron-free catalyst (-29 mV and -235 mV) and comparable to those of Pt/C (28 mV and -237 mV) with the same loading. The electrocatalysis and reaction kinetics results demonstrate that Fe-N/C-850 will be a promising catalyst at low cost for applications in fuel cells.
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Affiliation(s)
- Xinping He
- College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
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Asano S, Maki T, Sebastian V, Jensen KF, Mae K. Revealing the Formation Mechanism of Alloyed Pd-Ru Nanoparticles: A Conversion Measurement Approach Utilizing a Microflow Reactor. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:2236-2243. [PMID: 30642186 DOI: 10.1021/acs.langmuir.8b03516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The synthesis of alloyed nanoparticles has been studied extensively; however, the formation mechanisms involved remain unclear. Here, we reveal the detailed formation mechanism of alloyed nanoparticles in a Pd-Ru system, using a semibatch polyol method in which the simultaneous rapid reduction of both precursors was assumed to be the critical mechanism. We employed a microflow reactor to realize rapid heating and cooling. A significant difference in the reaction rate between the two precursors was observed. Pd was reduced within seconds, but the reduction of Ru was 2 orders of magnitude slower than that of Pd and was not as rapid as previously assumed. Further investigation of the semibatch method was performed to trace changes in the particle sizes and composition. Through quantitative and multilateral evidence, we concluded that the formation of low-crystallinity seeds, followed by solid-state diffusion, is the governing mechanism for the formation of alloyed Pd-Ru nanoparticles.
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Affiliation(s)
- Shusaku Asano
- Department of Chemical Engineering , Kyoto University , Kyoto 615-8510 , Japan
| | - Taisuke Maki
- Department of Chemical Engineering , Kyoto University , Kyoto 615-8510 , Japan
| | - Victor Sebastian
- Department of Chemical & Environmental Engineering , Aragon Institute of Nanoscience (INA), University of Zaragoza , Campus Rio Ebro , 50018 Zaragoza , Spain
- Centro de Investigación Biomédica en Red , CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , C/Monforte de Lemos 3-5, Pabellón 11 , 28029 Madrid , Spain
| | - Klavs F Jensen
- Department of Chemical Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
| | - Kazuhiro Mae
- Department of Chemical Engineering , Kyoto University , Kyoto 615-8510 , Japan
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