1
|
Monini V, Bonechi M, Bazzicalupi C, Bianchi A, Gentilesca P, Giurlani W, Innocenti M, Meoli A, Romano GM, Savastano M. Oxygen reduction reaction (ORR) in alkaline solution catalysed by an atomically precise catalyst based on a Pd(II) complex supported on multi-walled carbon nanotubes (MWCNTs). Electrochemical and structural considerations. Dalton Trans 2024; 53:2487-2500. [PMID: 38193252 DOI: 10.1039/d3dt03947a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
A new atomically precise, single-ion catalyst (MWCNT-LPd) for ORR (oxygen reduction reaction), consisting of a Pd(II) complex of a tetraazacycloalkane anchored on multiwalled carbon nanotubes, has been prepared through a supramolecular approach ensuring a uniform distribution of catalytic centres on the support surface. A tetraazacycloalkane was chosen to saturate the four coordination sites of the typical square planar coordination geometry of Pd(II) with the aim of ascertaining whether the metal ion must have free coordination sites to function effectively in the ORR or whether, as predicted by quantum mechanical calculations, the catalytic effect can be originated from an interaction of O2 in the fifth coordinative position. The results clearly demonstrated that tetracoordination of Pd(II) does not influence its catalytic capacity in the ORR. Electrodes based on this catalyst show ORR performance very close to that of commercial Pt electrodes, despite the low Pd(II) content (1.72% by weight) in the catalyst. The onset potential (Eon) value and the half-wave potential (E1/2) of the catalyst are, respectively, only 53 mV and 24 mV less positive than those observed for the Pt electrode and direct conversion of O2 to H2O reaches 85.0%, compared to 89% of the Pt electrode. Furthermore, a preliminary galvanostatic test (simulating a working fuel cell at a fixed potential) showed that the catalyst maintains its efficiency continuing to produce water throughout the process (the average number of electrons exchanged over time per O2 molecule remains close to 4).
Collapse
Affiliation(s)
- Valeria Monini
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Marco Bonechi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Carla Bazzicalupi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Antonio Bianchi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Research Unit of Florence, Via G. Giusti 9, 50121 Florence, Italy.
| | - Pietro Gentilesca
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Walter Giurlani
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Massimo Innocenti
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Research Unit of Florence, Via G. Giusti 9, 50121 Florence, Italy.
| | - Arianna Meoli
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Giammarco Maria Romano
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Matteo Savastano
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Research Unit of Florence, Via G. Giusti 9, 50121 Florence, Italy.
- Department of Human Sciences for the Promotion of Quality of Life, University San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy
| |
Collapse
|
2
|
Kawondera R, Bonechi M, Maccioni I, Giurlani W, Salzillo T, Venuti E, Mishra D, Fontanesi C, Innocenti M, Mehlana G, Mtangi W. Chiral "doped" MOFs: an electrochemical and theoretical integrated study. Front Chem 2023; 11:1215619. [PMID: 37614707 PMCID: PMC10442718 DOI: 10.3389/fchem.2023.1215619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/27/2023] [Indexed: 08/25/2023] Open
Abstract
This work reports on the electrochemical behaviour of Fe and Zn based metal-organic framework (MOF) compounds, which are "doped" with chiral molecules, namely: cysteine and camphor sulfonic acid. Their electrochemical behaviour was thoroughly investigated via "solid-state" electrochemical measurements, exploiting an "ad hoc" tailored experimental set-up: a paste obtained by carefully mixing the MOF with graphite powder is deposited on a glassy carbon (GC) surface. The latter serves as the working electrode (WE) in cyclic voltammetry (CV) measurements. Infrared (IR), X-ray diffraction (XRD) and absorbance (UV-Vis) techniques are exploited for a further characterization of the MOFs' structural and electronic properties. The experimental results are then compared with DFT based quantum mechanical calculations. The electronic and structural properties of the MOFs synthesized in this study depend mainly on the type of metal center, and to a minor extent on the chemical nature of the dopant.
Collapse
Affiliation(s)
- Rufaro Kawondera
- Institute of Materials Science, Processing and Engineering Technology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| | - Marco Bonechi
- Department of Chemistry, University of Firenze, Firenze, Italy
| | - Irene Maccioni
- Department of Chemistry, University of Firenze, Firenze, Italy
| | - Walter Giurlani
- Department of Chemistry, University of Firenze, Firenze, Italy
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Firenze, Italy
| | - Tommaso Salzillo
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Bologna, Italy
| | - Elisabetta Venuti
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Bologna, Italy
| | - Debabrata Mishra
- Department of Physics and Astrophysics, University of Delhi, New Delhi, India
| | - Claudio Fontanesi
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Firenze, Italy
- Department of Engineering “Enzo Ferrari” (DIEF), University of Modena, Modena, Italy
| | - Massimo Innocenti
- Department of Chemistry, University of Firenze, Firenze, Italy
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Firenze, Italy
- Center for Colloid and Surface Science (CSGI), Florence, Italy
| | - Gift Mehlana
- Department of Chemical Sciences, Midlands State University, Gweru, Zimbabwe
| | - Wilbert Mtangi
- Institute of Materials Science, Processing and Engineering Technology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| |
Collapse
|
3
|
Debgupta J, Lari L, Isaacs M, Carey J, McKenna KP, Lazarov VK, Chechik V, Douthwaite RE. Predictive Removal of Interfacial Defect-Induced Trap States between Titanium Dioxide Nanoparticles via Sub-Monolayer Zirconium Coating. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:660-671. [PMID: 36660098 PMCID: PMC9841567 DOI: 10.1021/acs.jpcc.2c06927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/13/2022] [Indexed: 06/17/2023]
Abstract
First principles modeling of anatase TiO2 surfaces and their interfacial contacts shows that defect-induced trap states within the band gap arise from intrinsic structural distortions, and these can be corrected by modification with Zr(IV) ions. Experimental testing of these predictions has been undertaken using anatase nanocrystals modified with a range of Zr precursors and characterized using structural and spectroscopic methods. Continuous-wave electron paramagnetic resonance (EPR) spectroscopy revealed that under illumination, nanoparticle-nanoparticle interfacial hole trap states dominate, which are significantly reduced after optimizing the Zr doping. Fabrication of nanoporous films of these materials and charge injection using electrochemical methods shows that Zr doping also leads to improved electron conductivity and mobility in these nanocrystalline systems. The simple methodology described here to reduce the concentration of interfacial defects may have wider application to improving the efficiency of systems incorporating metal oxide powders and films including photocatalysts, photovoltaics, fuel cells, and related energy applications.
Collapse
Affiliation(s)
| | - Leonardo Lari
- Department
of Physics, University of York, Heslington, York YO10 5DD, UK
| | - Mark Isaacs
- HarwellXPS, R92 Research Complex at Harwell, Rutherford Appleton Laboratories,
Harwell, Didcot OX11 0QS, UK
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - John Carey
- Department
of Physics, University of York, Heslington, York YO10 5DD, UK
| | - Keith P. McKenna
- Department
of Physics, University of York, Heslington, York YO10 5DD, UK
| | - Vlado K. Lazarov
- Department
of Physics, University of York, Heslington, York YO10 5DD, UK
| | - Victor Chechik
- Department
of Chemistry, University of York, York YO10 5DD, UK
| | | |
Collapse
|
4
|
Valbuena-Rus AM, Savastano M, Arranz-Mascarós P, Bazzicalupi C, Clares MP, Godino-Salido ML, Gutiérrez-Valero MD, Inclán M, Bianchi A, García-España E, López-Garzón R. Noncovalent Assembly and Catalytic Activity of Hybrid Materials Based on Pd Complexes Adsorbed on Multiwalled Carbon Nanotubes, Graphene, and Graphene Nanoplatelets. Inorg Chem 2022; 61:12610-12624. [PMID: 35926979 PMCID: PMC9387097 DOI: 10.1021/acs.inorgchem.2c01559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Green catalysts with excellent performance in Cu-free
Sonogashira
coupling reactions can be prepared by the supramolecular decoration
of graphene surfaces with Pd(II) complexes. Here we report the synthesis,
characterization, and catalytic properties of new catalysts obtained
by the surface decoration of multiwalled carbon nanotubes (MWCNTs),
graphene (G), and graphene nanoplatelets (GNPTs) with Pd(II) complexes
of tetraaza-macrocyclic ligands bearing one or two anchor functionalities.
The decoration of these carbon surfaces takes place under environmentally
friendly conditions (water, room temperature, aerobic) in two steps:
(i) π–π stacking attachment of the ligand via electron-poor
anchor group 6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxo-pyrimidine
and (ii) Pd(II) coordination from PdCl42–. Ligands are more efficiently adsorbed on the flat surfaces of G
and GNPTs than on the curved surfaces of MWCNTs. All catalysts work
very efficiently under mild conditions (50 °C, aerobic, 7 h),
giving a similar high yield (90% or greater) in the coupling of iodobenzene
with phenylacetylene to form diphenylacetylene in one catalytic cycle,
but catalysts based on G and GNPTs (especially on GNPTs) provide greater
catalytic efficiency in reuse (four cycles). The study also revealed
that the active centers of the ligand-Pd type decorating the support
surfaces are much more efficient than the Pd(0) and PdCl42– centers sharing the same surfaces. All of the
results allow a better understanding of the structural factors to
be controlled in order to obtain an optimal efficiency from similar
catalysts based on graphene supports. Green catalysts
with high efficiency in the Cu-free Sonogashira
C−C coupling reactions can be prepared by the supramolecular
functionalization of carbon materials.
Collapse
Affiliation(s)
- Alba M Valbuena-Rus
- Department of Inorganic and Organic Chemistry, University of Jaén, 23071 Jaen, Spain
| | - Matteo Savastano
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.,National Interuniversity Consortium of Materials Science and Technology (INSTM), Via G. Giusti 9, 50121 Florence, Italy
| | | | - Carla Bazzicalupi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
| | - María P Clares
- ICMol, Department of Inorganic Chemistry, University of Valencia, C/Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - María L Godino-Salido
- Department of Inorganic and Organic Chemistry, University of Jaén, 23071 Jaen, Spain
| | | | - Mario Inclán
- ICMol, Department of Inorganic Chemistry, University of Valencia, C/Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Antonio Bianchi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy
| | - Enrique García-España
- ICMol, Department of Inorganic Chemistry, University of Valencia, C/Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Rafael López-Garzón
- Department of Inorganic and Organic Chemistry, University of Jaén, 23071 Jaen, Spain
| |
Collapse
|
5
|
Garcia LM, Zambiazi PJ, Chair K, Doan TD, Ramos AS, Nandenha J, De Souza RFB, Otubo L, Duong A, O. Neto A. cis-[6-(Pyridin-2-yl)-1,3,5-triazine-2,4-diamine](dichloride) Palladium(II)-Based Electrolyte Membrane Reactors for Partial Oxidation Methane to Methanol. ACS OMEGA 2022; 7:24249-24255. [PMID: 35874252 PMCID: PMC9301691 DOI: 10.1021/acsomega.2c01463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Methane is an abundant resource and the main constituent of natural gas. It can be converted into higher value-added products and as a subproduct of electricity co-generation. The application of polymer electrolyte reactors for the partial oxidation of methane to methanol to co-generate power and chemical products is a topic of great interest for gas and petroleum industries, especially with the use of materials with a lower amount of metals, such as palladium complex. In this study, we investigate the ideal relationship between cis-[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine(dichloride)palladium(II)] (Pd-complex) nanostructure and carbon to obtain a stable, conductive, and functional reagent diffusion electrode. The physical and structural properties of the material were analyzed by Fourier transform infrared (FT-IR) and Raman spectroscopies, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques. The electrocatalytic activity studies revealed that the most active proportion was 20% of Pd-complex supported on carbon (m/m), which was measured with lower values of open-circuit and power density but with higher efficiency in methanol production with reaction rates of r = 4.2 mol L-1·h-1 at 0.05 V.
Collapse
Affiliation(s)
- Luis M.
S. Garcia
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
- Département
de Chimie, Biochimie et Physique, Institut de Recherchesur l’Hydrogène, Université du Québec
a Trois-Rivières, Trois-Rivières, Québec G9A5H7, Canada
| | - Priscilla J. Zambiazi
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
| | - Khaoula Chair
- Département
de Chimie, Biochimie et Physique, Institut de Recherchesur l’Hydrogène, Université du Québec
a Trois-Rivières, Trois-Rivières, Québec G9A5H7, Canada
| | - Tuan Duy Doan
- Département
de Chimie, Biochimie et Physique, Institut de Recherchesur l’Hydrogène, Université du Québec
a Trois-Rivières, Trois-Rivières, Québec G9A5H7, Canada
| | - Andrezza S. Ramos
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
| | - Julio Nandenha
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
| | - Rodrigo F. B. De Souza
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
| | - Larissa Otubo
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
| | - Adam Duong
- Département
de Chimie, Biochimie et Physique, Institut de Recherchesur l’Hydrogène, Université du Québec
a Trois-Rivières, Trois-Rivières, Québec G9A5H7, Canada
| | - Almir O. Neto
- Instituto
de Pesquisas Energéticas e Nucleares, IPEN/CNEN−SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil
| |
Collapse
|
6
|
Savastano M, Boscaro F, Bianchi A. Metal Coordination Properties of a Chromophoric Desferrioxamine (DFO) Derivative: Insight on the Coordination Stoichiometry and Thermodynamic Stability of Zr 4+ Complexes. Molecules 2021; 27:molecules27010184. [PMID: 35011419 PMCID: PMC8746621 DOI: 10.3390/molecules27010184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/16/2022] Open
Abstract
Desferrioxamine (DFO) is the current "gold standard" chelator for 89Zr4+, which is used to label monoclonal antibodies for applications in immunopositron emission tomography. Recently, controversial data have been reported regarding the speciation and the stability of the complexes formed by DFO with Zr4+ in solution. To shed some light on this point, we studied the coordination properties in solution ofa chromophoric DFO derivative bearing a substituted pyrimidine residue (DFO-Pm) toward several metal ions (Zr4+, Cu2+, Zn2+, Mg2+, Ca2+, Na+, K+). Potentiometric titrations showed that DFO-Pm and pristine DFO form complexes with very similar stoichiometry and stability. DFO-Pm, which can consequently be taken as a model system for DFO, provides a photochemical response to metal coordination that can be used to further define the complexes formed. In the critical case of Zr4+, spectrophotometric measurements allowed the verification of the formation of 1:1 and 2:3 complexes that, together with 2:2 complexes form the coordination model that was obtained through the use of our potentiometric measurements. Additionally, mass spectrometry measurements verified the formation of 1:1 and 2:3 complexes and showed that 1:2 species can be easily generated through the fragmentation of the 2:3 species. In conclusion, the results obtained with DFO-Pm validate the complexation model of Zr4+/DFO composed of 1:1, 2:2, and 2:3 metal-to-ligand complexes. Convergences and conflicts with other works are addressed.
Collapse
Affiliation(s)
- Matteo Savastano
- Department of Chemistry “Ugo Schiff”, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy;
- Correspondence:
| | - Francesca Boscaro
- Centro Interdipartimentale di Spettrometria di Massa (CISM), University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy;
| | - Antonio Bianchi
- Department of Chemistry “Ugo Schiff”, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy;
| |
Collapse
|
7
|
On the Oxygen Reduction Reaction Mechanism Catalyzed by Pd Complexes on 2D Carbon. A Theoretical Study. Catalysts 2021. [DOI: 10.3390/catal11070764] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Oxygen Reduction Reaction (ORR) is the bottle-neck strategic reaction ruling the fuel cell efficiency process. The slow kinetics of the reaction require highly effective electrocatalysts for proper boosting. In this field, composite catalysts formed by carbon nanotubes functionalized with palladium(II) complexes showed surprising catalytic activity comparable to those of a commercial Pt electrode, but the catalytic mechanisms of these materials still remain open to discussion. In this paper, we propose the combination of experimental and theoretical results to unfold the elementary reaction steps underlying the ORR catalysis.
Collapse
|
8
|
Savastano M, Passaponti M, Giurlani W, Lari L, Calisi N, Delgado-Pinar E, Serrano ES, Garcia-España E, Innocenti M, Lazarov VK, Bianchi A. Linear, tripodal, macrocyclic: Ligand geometry and ORR activity of supported Pd(II) complexes. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|