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Barrio J, Pedersen A, Sarma SC, Bagger A, Gong M, Favero S, Zhao CX, Garcia-Serres R, Li AY, Zhang Q, Jaouen F, Maillard F, Kucernak A, Stephens IEL, Titirici MM. FeNC Oxygen Reduction Electrocatalyst with High Utilization Penta-Coordinated Sites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211022. [PMID: 36739474 DOI: 10.1002/adma.202211022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/11/2023] [Indexed: 06/18/2023]
Abstract
Atomic Fe in N-doped carbon (FeNC) electrocatalysts for oxygen (O2 ) reduction at the cathode of proton exchange membrane fuel cells are the most promising alternative to platinum-group-metal catalysts. Despite recent progress on atomic FeNC O2 reduction, their controlled synthesis and stability for practical applications remain challenging. A two-step synthesis approach has recently led to significant advances in terms of Fe-loading and mass activity; however, the Fe utilization remains low owing to the difficulty of building scaffolds with sufficient porosity that electrochemically exposes the active sites. Herein, this issue is addressed by coordinating Fe in a highly porous nitrogen-doped carbon support (≈3295 m2 g-1 ), prepared by pyrolysis of inexpensive 2,4,6-triaminopyrimidine and a Mg2+ salt active site template and porogen. Upon Fe coordination, a high electrochemical active site density of 2.54 × 1019 sites gFeNC -1 and a record 52% FeNx electrochemical utilization based on in situ nitrite stripping are achieved. The Fe single atoms are characterized pre- and post-electrochemical accelerated stress testing by aberration-corrected high-angle annular dark field scanning transmission electron microscopy, showing no Fe clustering. Moreover, ex situ X-ray absorption spectroscopy and low-temperature Mössbauer spectroscopy suggest the presence of penta-coordinated Fe sites, which are further studied by density functional theory calculations.
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Affiliation(s)
- Jesús Barrio
- Department of Materials, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Angus Pedersen
- Department of Materials, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Saurav Ch Sarma
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Alexander Bagger
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Mengjun Gong
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Silvia Favero
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Chang-Xin Zhao
- Department of Chemical Engineering, Tsinghua University, 1 Tsinghua Road, Beijing, 100084, P. R. China
| | - Ricardo Garcia-Serres
- Chemistry and Biology of Metals Laboratory, CNRS, CEA, IRIG, University Grenoble Alpes, 17 Rue Des Martyrs, Grenoble, 38000, France
| | - Alain Y Li
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Qiang Zhang
- Department of Chemical Engineering, Tsinghua University, 1 Tsinghua Road, Beijing, 100084, P. R. China
| | - Frédéric Jaouen
- Institute of Molecular Chemistry and Materials Sciences, CNRS, ENSCM, University of Montpellier, 1919 route de Mende, Montpellier, 34293, France
| | - Frédéric Maillard
- Laboratory of Electrochemistry and Physico-Chemistry of Materials and Interfaces (LEPMI), CNRS, University Savoie Mont-Blanc, Grenoble-INP, University Grenoble Alpes, Grenoble, 38000, France
| | - Anthony Kucernak
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Ifan E L Stephens
- Department of Materials, Royal School of Mines, Imperial College London, London, SW7 2AZ, UK
| | - Maria-Magdalena Titirici
- Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, UK
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aobaku, Sendai, Miyagi, 980-8577, Japan
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Heymann L, Bittinger SC, Klinke C. Molecular Doping of Electrochemically Prepared Triazine-Based Carbon Nitride by 2,4,6-Triaminopyrimidine for Improved Photocatalytic Properties. ACS OMEGA 2018; 3:17042-17048. [PMID: 30613810 PMCID: PMC6312646 DOI: 10.1021/acsomega.8b02659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
Copolymerization of melamine with 2,4,6-triaminopyrimidine (TAP) in an electrochemically induced polymerization process leads to the formation of molecular doped poly(triazine imide) (PTI). The polymerization is based on the electrolysis of water and evolving radicals during this process. The incorporation of TAP is shown by techniques such as elemental analysis, Fourier transform infrared and NMR spectroscopies, and powder X-ray diffraction, and it is shown that the carbon content can be tuned by the variation of the molar ratio of the two precursors. This incorporation of TAP directly influences the electronic structure of PTI and as a result, a red shift can be observed in UV-vis spectroscopy. The smaller band gap and the increased absorption in the visible range lead to improved photocatalytic properties. In dye degradation experiments, it was possible to observe an increase of the rate of the degradation of methylene blue by a factor of 4 in comparison to undoped PTI or 7 if compared to melon.
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Affiliation(s)
- Leonard Heymann
- Institute
of Physical Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Sophia C. Bittinger
- Institute
of Physical Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Christian Klinke
- Institute
of Physical Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
- Chemistry
Department, Swansea University, Singleton Park, SA2 8PP Swansea, U.K.
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Nimthong R, Chamchong S, Pakawatchai C, Mokhagul J, Wattanakanjana Y. Bis(2,4,6-tri-amino-pyrimidin-1-ium) sulfate penta-hydrate. Acta Crystallogr Sect E Struct Rep Online 2013; 69:o1266-o1267. [PMID: 24109349 PMCID: PMC3793762 DOI: 10.1107/s1600536813019223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 07/11/2013] [Indexed: 06/02/2023]
Abstract
The asymmetric unit of the title salt, 2C4H8N5 (+)·SO4 (2-)·5H2O, contains four 2,4,6-tri-amino-pyrimidinium (TAPH(+)) cations, two sulfate anions and ten lattice water mol-ecules. Each two of the four TAPH(+) cations form dimers via N-H⋯N hydrogen bonds between the amino groups and the unprotonated pyrimidine N atoms [graph-set motif R 2 (2)(8)]. The (TAPH(+))2 dimers, in turn, form slightly offset infinite π-π stacks parallel to [010], with centroid-centroid distances between pyrimidine rings of 3.5128 (15) and 3.6288 (16) Å. Other amino H atoms, as well as the pyrimidinium N-H groups, are hydrogen-bonded to sulfate and lattice water O atoms. The SO4 (2-) anions and water mol-ecules are inter-connected with each other via O-H⋯O hydrogen bonds. The combination of hydrogen-bonding inter-actions and π-π stacking leads to the formation of a three-dimensional network with alternating columns of TAPH(+) cations and channels filled with sulfate anions and water mol-ecules. One of the sulfate anions shows a minor disorder by a ca 37° rotation around one of the S-O bonds [occupancy ratio of the two sets of sites 0.927 (3):0.073 (3)]. One water mol-ecule is disordered over two mutually exclusive positions with an occupancy ratio of 0.64 (7):0.36 (7).
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Affiliation(s)
- Ruthairat Nimthong
- Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Siva Chamchong
- Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Chaveng Pakawatchai
- Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Jedsada Mokhagul
- Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Yupa Wattanakanjana
- Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
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De Rosa M, Arnold D. Aromaticity and Aminopyrroles: Desmotropy and Solution Tautomerism of 1H-Pyrrol-3-aminium and 1H-Pyrrol-3(2H)-iminium Cation: A Stable σ-Complex. J Org Chem 2013; 78:1107-12. [DOI: 10.1021/jo302457y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael De Rosa
- Department of Chemistry, Penn State Brandywine, 25 Yearsley Mill Road, Media,
Pennsylvania 19063, United States
| | - David Arnold
- Department of Chemistry, Penn State Brandywine, 25 Yearsley Mill Road, Media,
Pennsylvania 19063, United States
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Study of the protonation (methylation) position and tautomeric structure of thiopyrimidine derivatives by 2D 1H—15H NMR HSQC/HMBC. Experimental approach and theoretical modeling. Russ Chem Bull 2010. [DOI: 10.1007/s11172-009-0008-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Dračínský M, Holý A, Jansa P, Kovačková S, Buděšínský M. Isotopic Exchange of Hydrogen at C-5 in Pyrimidine Derivatives: Tautomers with an sp3-Hybridised C-5 Carbon Atom. European J Org Chem 2009. [DOI: 10.1002/ejoc.200900529] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kozlov AV, Semenov VE, Mikhailov AS, Aganov AV, Smith MB, Reznik VS, Latypov SK. Preferential Protonation and Methylation Site of Thiopyrimidine Derivatives in Solution: NMR Data. J Phys Chem B 2008; 112:3259-67. [DOI: 10.1021/jp710952r] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Artem V. Kozlov
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
| | - Vyacheslav E. Semenov
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
| | - Anatoliy S. Mikhailov
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
| | - Albert V. Aganov
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
| | - Michael B. Smith
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
| | - Vladimir S. Reznik
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
| | - Shamil K. Latypov
- Institute of Organic and Physical Chemistry, Arbuzov Str. 8, Kazan, 420088, Russian Federation, Kazan State University, Kazan, 420008, Russian Federation, and University of Connecticut, 55 North Eagleville Road, 4-60, Storrs, Connecticut 06269-3060
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