1
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Venkatesh A, Casano G, Wei R, Rao Y, Lingua H, Karoui H, Yulikov M, Ouari O, Emsley L. Rational Design of Dinitroxide Polarizing Agents for Dynamic Nuclear Polarization to Enhance Overall NMR Sensitivity. Angew Chem Int Ed Engl 2024; 63:e202317337. [PMID: 38193258 DOI: 10.1002/anie.202317337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 01/10/2024]
Abstract
We evaluate the overall sensitivity gains provided by a series of eighteen nitroxide biradicals for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and 100 K, including eight new biradicals. We find that in the best performing group the factors contributing to the overall sensitivity gains, namely the DNP enhancement, the build-up time, and the contribution factor, often compete with each other leading to very similar overall sensitivity across a range of biradicals. NaphPol and HydroPol are found to provide the best overall sensitivity factors, in organic and aqueous solvents respectively. One of the new biradicals, AMUPolCbm, provides high sensitivity for all three solvent formulations measured here, and can be considered to be a "universal" polarizing agent.
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Affiliation(s)
- Amrit Venkatesh
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- Current address: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Gilles Casano
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Ran Wei
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Yu Rao
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Hugo Lingua
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Hakim Karoui
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Maxim Yulikov
- Laboratory of Physical Chemistry, Department of Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Olivier Ouari
- Aix Marseille Univ, CNRS, Institut de Chimie Radicalaire UMR 7273, 13013, Marseille, France
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
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2
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Kapoor A, Rajput JK. Staudinger k
etene–imine
[2+2] cycloaddition of novel azomethines to synthesize biologically active azetidinone derivatives and their in vitro antimicrobial studies. J Heterocycl Chem 2021. [DOI: 10.1002/jhet.4357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Atul Kapoor
- Department of Chemistry Dr. B.R Ambedkar National Institute of Technology Jalandhar India
| | - Jaspreet Kaur Rajput
- Department of Chemistry Dr. B.R Ambedkar National Institute of Technology Jalandhar India
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3
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Rodriguez-Gomez A, Chowdhury AD, Caglayan M, Bau JA, Abou-Hamad E, Gascon J. Non-oxidative dehydrogenation of isobutane over supported vanadium oxide: nature of the active sites and coke formation. Catal Sci Technol 2020. [DOI: 10.1039/d0cy01174f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We combine Raman spectroscopy, EPR, XPS, temperature programmed reduction, XRD, 51V MAS ssNMR, TEM and N2-physisorption to unravel structure–activity relationships during the non-oxidative dehydrogenation of isobutane over a V based catalyst.
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Affiliation(s)
- Alberto Rodriguez-Gomez
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Abhishek Dutta Chowdhury
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Mustafa Caglayan
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Jeremy A. Bau
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Edy Abou-Hamad
- Core Labs
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
| | - Jorge Gascon
- KAUST Catalysis Center (KCC)
- Advanced Catalytic Materials
- King Abdullah University of Science and Technology
- Thuwal 23955
- Saudi Arabia
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4
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Lin J, Zhao W, Huang F. Facile and economical synthesis of nitrogen-rich tantalum nitrides via an ammonia looping process under confined space. NEW J CHEM 2020. [DOI: 10.1039/d0nj01390k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Nitrogen-rich tantalum nitrides are synthesized via an ammonium looping process by pyrolyzing a single-source precursor, considerably reducing ammonia usage.
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Affiliation(s)
- Jie Lin
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- P. R. China
| | - Wei Zhao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- P. R. China
| | - Fuqiang Huang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- P. R. China
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5
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Dutta Chowdhury A, Yarulina I, Abou-Hamad E, Gurinov A, Gascon J. Surface enhanced dynamic nuclear polarization solid-state NMR spectroscopy sheds light on Brønsted-Lewis acid synergy during the zeolite catalyzed methanol-to-hydrocarbon process. Chem Sci 2019; 10:8946-8954. [PMID: 32190235 PMCID: PMC7068724 DOI: 10.1039/c9sc02215e] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/20/2019] [Indexed: 02/02/2023] Open
Abstract
After a prolonged effort over two decades, the reaction mechanism of the zeolite-catalyzed methanol-to-hydrocarbon (MTH) process is now well-understood: the so-called 'direct mechanism' (via direct coupling of two methanol molecules) is responsible for the formation of the initial carbon-carbon bonds, while the hydrocarbon pool (HCP)-based dual cycle mechanism is responsible for the formation of reaction products. While most of the reaction events occur at zeolite Brønsted acid sites, the addition of Lewis acid sites (i.e., via the introduction of alkaline earth cations like calcium) has been shown to inhibit the formation of deactivating coke species and hence increase the catalyst lifetime. With the aim to have an in-depth mechanistic understanding, herein, we employ magic angle spinning surface-enhanced dynamic nuclear polarization solid-state NMR spectroscopy to illustrate that the inclusion of Lewis acidity prevents the formation of carbene/ylide species on the zeolite, directly affecting the equilibrium between arene and olefin cycles of the HCP mechanism and hence regulating the ultimate product selectivity and catalyst lifetime.
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Affiliation(s)
- Abhishek Dutta Chowdhury
- King Abdullah University of Science and Technology , KAUST Catalysis Center , Advanced Catalytic Materials , Thuwal 23955 , Saudi Arabia . ;
| | - Irina Yarulina
- King Abdullah University of Science and Technology , KAUST Catalysis Center , Advanced Catalytic Materials , Thuwal 23955 , Saudi Arabia . ;
| | - Edy Abou-Hamad
- King Abdullah University of Science and Technology , KAUST Core Labs , Thuwal 23955 , Saudi Arabia .
| | - Andrei Gurinov
- King Abdullah University of Science and Technology , KAUST Core Labs , Thuwal 23955 , Saudi Arabia .
| | - Jorge Gascon
- King Abdullah University of Science and Technology , KAUST Catalysis Center , Advanced Catalytic Materials , Thuwal 23955 , Saudi Arabia . ;
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6
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Hanrahan MP, Chen Y, Blome-Fernández R, Stein JL, Pach GF, Adamson MAS, Neale NR, Cossairt BM, Vela J, Rossini AJ. Probing the Surface Structure of Semiconductor Nanoparticles by DNP SENS with Dielectric Support Materials. J Am Chem Soc 2019; 141:15532-15546. [PMID: 31456398 DOI: 10.1021/jacs.9b05509] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Surface characterization is crucial for understanding how the atomic-level structure affects the chemical and photophysical properties of semiconducting nanoparticles (NPs). Solid-state nuclear magnetic resonance spectroscopy (NMR) is potentially a powerful technique for the characterization of the surface of NPs, but it is hindered by poor sensitivity. Dynamic nuclear polarization surface enhanced NMR spectroscopy (DNP SENS) has previously been demonstrated to enhance the sensitivity of surface-selective solid-state NMR experiments by 1-2 orders of magnitude. Established sample preparations for DNP SENS experiments on NPs require the dilution of the NPs on mesoporous silica. Using hexagonal boron nitride (h-BN) to disperse the NPs doubles DNP enhancements and absolute sensitivity in comparison to standard protocols with mesoporous silica. Alternatively, precipitating the NPs as powders, mixing them with h-BN, and then impregnating the powdered mixture with radical solution leads to further 4-fold sensitivity enhancements by increasing the concentration of NPs in the final sample. This modified procedure provides a factor of 9 improvement in NMR sensitivity in comparison to previously established DNP SENS procedures, enabling challenging homonuclear and heteronuclear 2D NMR experiments on CdS, Si, and Cd3P2 NPs. These experiments allow NMR signals from the surface, subsurface, and core sites to be observed and assigned. For example, we demonstrate the acquisition of DNP-enhanced 2D 113Cd-113Cd correlation NMR experiments on CdS NPs and natural isotropic abundance 2D 13C-29Si HETCOR of functionalized Si NPs. These experiments provide a critical understanding of NP surface structures.
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Affiliation(s)
- Michael P Hanrahan
- Iowa State University , Department of Chemistry , Ames , Iowa 50011 , United States.,US DOE Ames Laboratory , Ames , Iowa 50011 , United States
| | - Yunhua Chen
- Iowa State University , Department of Chemistry , Ames , Iowa 50011 , United States.,US DOE Ames Laboratory , Ames , Iowa 50011 , United States
| | | | - Jennifer L Stein
- University of Washington , Department of Chemistry , Seattle , Washington 98195 , United States
| | - Gregory F Pach
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - Marquix A S Adamson
- Iowa State University , Department of Chemistry , Ames , Iowa 50011 , United States
| | - Nathan R Neale
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - Brandi M Cossairt
- University of Washington , Department of Chemistry , Seattle , Washington 98195 , United States
| | - Javier Vela
- Iowa State University , Department of Chemistry , Ames , Iowa 50011 , United States.,US DOE Ames Laboratory , Ames , Iowa 50011 , United States
| | - Aaron J Rossini
- Iowa State University , Department of Chemistry , Ames , Iowa 50011 , United States.,US DOE Ames Laboratory , Ames , Iowa 50011 , United States
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7
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Al Maksoud W, Gevers LE, Vittenet J, Ould-Chikh S, Telalovic S, Bhatte K, Abou-Hamad E, Anjum DH, Hedhili MN, Vishwanath V, Alhazmi A, Almusaiteer K, Basset JM. A strategy to convert propane to aromatics (BTX) using TiNp 4 grafted at the periphery of ZSM-5 by surface organometallic chemistry. Dalton Trans 2019; 48:6611-6620. [PMID: 31017165 DOI: 10.1039/c9dt00905a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The direct conversion of propane into aromatics (BTX) using modified ZSM-5 was achieved with a strategy of "catalysis by design". In contrast to the classical mode of action of classical aromatization catalysts which are purely based on acidity, we have designed the catalyst associating two functions: One function (Ti-hydride) was selected to activate the C-H bond of propane by σ-bond metathesis to further obtain olefin by β-H elimination and the other function (Brønsted acid) being responsible for the oligomerization, cyclization, and aromatization. This bifunctional catalyst was obtained by selectively grafting a bulky organometallic complex of tetrakis(neopentyl)titanium (TiNp4) at the external surface (external silanol ([triple bond, length as m-dash]Si-OH) group) of [H-ZSM-5300] to obtain [Ti/ZSM-5] catalyst 1. This metal was chosen to activate the C-H bond of paraffin at the periphery of the ZSM-5 while maintaining the Brønsted acid properties of the internal [H-ZSM-5] for oligomerization, cyclization, and aromatization. Catalyst 2 [Ti-H/ZSM-5] was obtained after treatment under H2 at 550 °C of freshly prepared catalyst 1 ([Ti/ZSM-5]) and catalyst 1 was thoroughly characterized by ICP analysis, DRIFT, XRD, N2-physisorption, multinuclear solid-state NMR, XPS and HR-TEM analysis including STEM imaging. The conversion of propane to aromatics was studied in a dynamic flow reactor. With the pristine [H-ZSM-5300] catalyst, the conversion of propane is very low. However, with [Ti-H/ZSM-5] catalyst 2 under the same reaction conditions, the conversion of propane remains significant during 60 h of the reaction (ca. 22%). Furthermore, the [Ti-H/ZSM-5] catalyst shows a good and stable selectivity (55%) for aromatics (BTX) of time on stream. With 2, it was found that the Ti remains at the periphery of the [H-ZSM-5] even after reaction time.
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Affiliation(s)
- Walid Al Maksoud
- King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal, 23955-6900, Saudi Arabia.
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8
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Ma W, Qiao Y, Theyssen N, Zhou Q, Li D, Ding B, Wang D, Hou Z. A mononuclear tantalum catalyst with a peroxocarbonate ligand for olefin epoxidation in compressed CO2. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00056a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A mononuclear tantalum complex bonded to a peroxocarbonate ligand has been proved to be particularly important in the epoxidation reactions.
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Affiliation(s)
- Wenbao Ma
- Key Laboratory for Advanced Materials
- Research Institute of Industrial Catalysis
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Yunxiang Qiao
- Max-Planck-Institut für Kohlenforschung
- 45470 Mülheim an der Ruhr
- Germany
| | - Nils Theyssen
- Max-Planck-Institut für Kohlenforschung
- 45470 Mülheim an der Ruhr
- Germany
| | - Qingqing Zhou
- Key Laboratory for Advanced Materials
- Research Institute of Industrial Catalysis
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Difan Li
- Key Laboratory for Advanced Materials
- Research Institute of Industrial Catalysis
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Bingjie Ding
- Key Laboratory for Advanced Materials
- Research Institute of Industrial Catalysis
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Dongqi Wang
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing 100049
- China
| | - Zhenshan Hou
- Key Laboratory for Advanced Materials
- Research Institute of Industrial Catalysis
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
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9
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Bresciani G, Marchetti F, Rizzi G, Gabbani A, Pineider F, Pampaloni G. Metal N,N-dialkylcarbamates as easily available catalytic precursors for the carbon dioxide/propylene oxide coupling under ambient conditions. J CO2 UTIL 2018. [DOI: 10.1016/j.jcou.2018.09.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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10
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Ma W, Yuan H, Wang H, Zhou Q, Kong K, Li D, Yao Y, Hou Z. Identifying Catalytically Active Mononuclear Peroxoniobate Anion of Ionic Liquids in the Epoxidation of Olefins. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04443] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wenbao Ma
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Haiyang Yuan
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Haifeng Wang
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Qingqing Zhou
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Kang Kong
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Difan Li
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Yefeng Yao
- Physics Department and Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, People’s Republic of China
| | - Zhenshan Hou
- Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
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11
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Zwaschka G, Rondelli M, Krause M, Rötzer MD, Hedhili MN, Heiz U, Basset JM, Schweinberger FF, D'Elia V. Supported sub-nanometer Ta oxide clusters as model catalysts for the selective epoxidation of cyclooctene. NEW J CHEM 2018. [DOI: 10.1039/c7nj04275b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The preparation of organic ligand-free, isolated and catalytically active tantalum oxide complexes (Ta1) and small clusters (Tan>1) on flat silicate support was accomplished by ultra-high vacuum (UHV) techniques followed by oxidation in air.
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Affiliation(s)
- G. Zwaschka
- Technical University of Munich
- Catalysis Research Center and Chemistry Department
- Chair of Physical Chemistry
- 85748 Garching
- Germany
| | - M. Rondelli
- Technical University of Munich
- Catalysis Research Center and Chemistry Department
- Chair of Physical Chemistry
- 85748 Garching
- Germany
| | - M. Krause
- Technical University of Munich
- Catalysis Research Center and Chemistry Department
- Chair of Physical Chemistry
- 85748 Garching
- Germany
| | - M. D. Rötzer
- Technical University of Munich
- Catalysis Research Center and Chemistry Department
- Chair of Physical Chemistry
- 85748 Garching
- Germany
| | - M. N. Hedhili
- King Abdullah University of Science and Technology (KAUST)
- Imaging and Characterization Core Lab
- Thuwal 23955-6900
- Kingdom of Saudi Arabia
| | - U. Heiz
- Technical University of Munich
- Catalysis Research Center and Chemistry Department
- Chair of Physical Chemistry
- 85748 Garching
- Germany
| | - J.-M. Basset
- King Abdullah University of Science and Technology (KAUST)
- Kaust Catalysis Center (KCC)
- Thuwal 23955-6900
- Kingdom of Saudi Arabia
| | - F. F. Schweinberger
- Technical University of Munich
- Catalysis Research Center and Chemistry Department
- Chair of Physical Chemistry
- 85748 Garching
- Germany
| | - V. D'Elia
- King Abdullah University of Science and Technology (KAUST)
- Kaust Catalysis Center (KCC)
- Thuwal 23955-6900
- Kingdom of Saudi Arabia
- Vidyasirimedhi Institute of Science and Technology (VISTEC)
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