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Wu L, Longo A, Dzade NY, Sharma A, Hendrix MMRM, Bol AA, de Leeuw NH, Hensen EJM, Hofmann JP. The Origin of High Activity of Amorphous MoS 2 in the Hydrogen Evolution Reaction. CHEMSUSCHEM 2019; 12:4383-4389. [PMID: 31319020 PMCID: PMC6852468 DOI: 10.1002/cssc.201901811] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Indexed: 06/02/2023]
Abstract
Molybdenum disulfide (MoS2 ) and related transition metal chalcogenides can replace expensive precious metal catalysts such as Pt for the hydrogen evolution reaction (HER). The relations between the nanoscale properties and HER activity of well-controlled 2H and Li-promoted 1T phases of MoS2 , as well as an amorphous MoS2 phase, have been investigated and a detailed comparison is made on Mo-S and Mo-Mo bond analysis under operando HER conditions, which reveals a similar bond structure in 1T and amorphous MoS2 phases as a key feature in explaining their increased HER activity. Whereas the distinct bond structure in 1T phase MoS2 is caused by Li+ intercalation and disappears under harsh HER conditions, amorphous MoS2 maintains its intrinsic short Mo-Mo bond feature and, with that, its high HER activity. Quantum-chemical calculations indicate similar electronic structures of small MoS2 clusters serving as models for amorphous MoS2 and the 1T phase MoS2 , showing similar Gibbs free energies for hydrogen adsorption (ΔGH* ) and metallic character.
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77
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Haandel L, Longo A, Bras W, Hensen EJM, Weber T. Activation of Co−Mo−S Hydrodesulfurization Catalysts Under Refinery Conditions‐A Combined SAXS/XAS Study. ChemCatChem 2019. [DOI: 10.1002/cctc.201901390] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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78
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Li H, Wu H, Zhang H, Su Y, Yang S, Hensen EJM. A Facile Direct Route to N-(Un)substituted Lactams by Cycloamination of Oxocarboxylic Acids without External Hydrogen. CHEMSUSCHEM 2019; 12:3778-3784. [PMID: 31278839 PMCID: PMC6772168 DOI: 10.1002/cssc.201901780] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Indexed: 05/22/2023]
Abstract
Lactams are privileged in bioactive natural products and pharmaceutical agents and widely featured in functional materials. This study presents a novel versatile approach to the direct synthesis of lactams from oxocarboxylic acids without catalyst or external hydrogen. The method involves the in situ release of formic acid from formamides induced by water to facilitate efficient cycloamination. Water also suppresses the formation of byproducts. This unconventional pathway is elucidated by a combination of model experiments and density functional theory calculations, whereby cyclic imines (5-methyl-3,4-dihydro-2-pyrrolone and its tautomeric structures) are found to be favorable intermediates toward lactam formation, in contrast to the conventional approach encompassing cascade reductive amination and cyclization. This sustainable and simple protocol is broadly applicable for the efficient production of various N-unsubstituted and N-substituted lactams.
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79
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Garcia‐Torregrosa I, Goryachev A, Hofmann JP, Hensen EJM, Weckhuysen BM. Efficient and Highly Transparent Ultra‐Thin Nickel‐Iron Oxy‐hydroxide Catalyst for Oxygen Evolution Prepared by Successive Ionic Layer Adsorption and Reaction. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900131] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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80
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Vrijburg WL, Moioli E, Chen W, Zhang M, Terlingen BJP, Zijlstra B, Filot IAW, Züttel A, Pidko EA, Hensen EJM. Efficient Base-Metal NiMn/TiO2 Catalyst for CO2 Methanation. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01968] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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81
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Wu L, Dzade NY, Yu M, Mezari B, van Hoof AJF, Friedrich H, de Leeuw NH, Hensen EJM, Hofmann JP. Unraveling the Role of Lithium in Enhancing the Hydrogen Evolution Activity of MoS 2: Intercalation versus Adsorption. ACS ENERGY LETTERS 2019; 4:1733-1740. [PMID: 31328171 PMCID: PMC6630958 DOI: 10.1021/acsenergylett.9b00945] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/27/2019] [Indexed: 05/13/2023]
Abstract
Molybdenum disulfide (MoS2) is a highly promising catalyst for the hydrogen evolution reaction (HER) to realize large-scale artificial photosynthesis. The metallic 1T'-MoS2 phase, which is stabilized via the adsorption or intercalation of small molecules or cations such as Li, shows exceptionally high HER activity, comparable to that of noble metals, but the effect of cation adsorption on HER performance has not yet been resolved. Here we investigate in detail the effect of Li adsorption and intercalation on the proton reduction properties of MoS2. By combining spectroscopy methods (infrared of adsorbed NO, 7Li solid-state nuclear magnetic resonance, and X-ray photoemission and absorption) with catalytic activity measurements and theoretical modeling, we infer that the enhanced HER performance of Li x MoS2 is predominantly due to the catalytic promotion of edge sites by Li.
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82
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Zijlstra B, Broos RJP, Chen W, Oosterbeek H, Filot IAW, Hensen EJM. Coverage Effects in CO Dissociation on Metallic Cobalt Nanoparticles. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01967] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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83
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Bolshakov A, Romero Hidalgo DE, van Hoof AJF, Kosinov N, Hensen EJM. Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization. ChemCatChem 2019. [DOI: 10.1002/cctc.201900974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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84
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Bolshakov A, Romero Hidalgo DE, van Hoof AJF, Kosinov N, Hensen EJM. Front Cover: Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization (ChemCatChem 12/2019). ChemCatChem 2019. [DOI: 10.1002/cctc.201900973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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85
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Kosinov N, Uslamin EA, Meng L, Parastaev A, Liu Y, Hensen EJM. Reversible Nature of Coke Formation on Mo/ZSM‐5 Methane Dehydroaromatization Catalysts. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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86
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Wannapakdee W, Meng L, van Hoof AJF, Bolshakov A, Wattanakit C, Hensen EJM. The Important Role of Rubidium Hydroxide in the Synthesis of Hierarchical ZSM-5 Zeolite Using Cetyltrimethylammonium as Structure-Directing Agent. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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87
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Bolshakov A, Romero Hidalgo DE, van Hoof AJF, Kosinov N, Hensen EJM. Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization. ChemCatChem 2019. [DOI: 10.1002/cctc.201900298] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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88
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Kosinov N, Uslamin EA, Meng L, Parastaev A, Liu Y, Hensen EJM. Reversible Nature of Coke Formation on Mo/ZSM-5 Methane Dehydroaromatization Catalysts. Angew Chem Int Ed Engl 2019; 58:7068-7072. [PMID: 30900346 PMCID: PMC6563702 DOI: 10.1002/anie.201902730] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Indexed: 11/18/2022]
Abstract
Non‐oxidative dehydroaromatization of methane over Mo/ZSM‐5 zeolite catalysts is a promising reaction for the direct conversion of abundant natural gas into liquid aromatics. Rapid coking deactivation hinders the practical implementation of this technology. Herein, we show that catalyst productivity can be improved by nearly an order of magnitude by raising the reaction pressure to 15 bar. The beneficial effect of pressure was found for different Mo/ZSM‐5 catalysts and a wide range of reaction temperatures and space velocities. High‐pressure operando X‐ray absorption spectroscopy demonstrated that the structure of the active Mo‐phase was not affected by operation at elevated pressure. Isotope labeling experiments, supported by mass‐spectrometry and 13C nuclear magnetic resonance spectroscopy, indicated the reversible nature of coke formation. The improved performance can be attributed to faster coke hydrogenation at increased pressure, overall resulting in a lower coke selectivity and better utilization of the zeolite micropore space.
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89
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Kim M, Su Y, Aoshima T, Fukuoka A, Hensen EJM, Nakajima K. Effective Strategy for High-Yield Furan Dicarboxylate Production for Biobased Polyester Applications. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00450] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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90
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Zhang L, Filot IAW, Su YQ, Liu JX, Hensen EJM. Understanding the Impact of Defects on Catalytic CO Oxidation of LaFeO 3-Supported Rh, Pd, and Pt Single-Atom Catalysts. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:7290-7298. [PMID: 30949277 PMCID: PMC6443215 DOI: 10.1021/acs.jpcc.9b01520] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 03/03/2019] [Indexed: 06/09/2023]
Abstract
Understanding the intrinsic catalytic properties of perovskite materials can accelerate the development of highly active and abundant complex oxide catalysts. Here, we performed a first-principles density functional theory study combined with a microkinetics analysis to comprehensively investigate the influence of defects on catalytic CO oxidation of LaFeO3 catalysts containing single atoms of Rh, Pd, and Pt. La defects and subsurface O vacancies considerably affect the local electronic structure of these single atoms adsorbed at the surface or replacing Fe in the surface of the perovskite. As a consequence, not only the stability of the introduced single atoms is enhanced but also the CO and O2 adsorption energies are modified. This also affects the barriers for CO oxidation. Uniquely, we find that the presence of La defects results in a much higher CO oxidation rate for the doped perovskite surface. A linear correlation between the activation barrier for CO oxidation and the surface O vacancy formation energy for these models is identified. Additionally, the presence of subsurface O vacancies only slightly promotes CO oxidation on the LaFeO3 surface with an adsorbed Rh atom. Our findings suggest that the introduction of La defects in LaFeO3-based environmental catalysts could be a promising strategy toward improved oxidation performance. The insights revealed herein guide the design of the perovskite-based three-way catalyst through compositional variation.
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91
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Pereira-Hernández XI, DeLaRiva A, Muravev V, Kunwar D, Xiong H, Sudduth B, Engelhard M, Kovarik L, Hensen EJM, Wang Y, Datye AK. Tuning Pt-CeO 2 interactions by high-temperature vapor-phase synthesis for improved reducibility of lattice oxygen. Nat Commun 2019; 10:1358. [PMID: 30911011 PMCID: PMC6433950 DOI: 10.1038/s41467-019-09308-5] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 02/15/2019] [Indexed: 12/02/2022] Open
Abstract
In this work, we compare the CO oxidation performance of Pt single atom catalysts (SACs) prepared via two methods: (1) conventional wet chemical synthesis (strong electrostatic adsorption–SEA) with calcination at 350 °C in air; and (2) high temperature vapor phase synthesis (atom trapping–AT) with calcination in air at 800 °C leading to ionic Pt being trapped on the CeO2 in a thermally stable form. As-synthesized, both SACs are inactive for low temperature (<150 °C) CO oxidation. After treatment in CO at 275 °C, both catalysts show enhanced reactivity. Despite similar Pt metal particle size, the AT catalyst is significantly more active, with onset of CO oxidation near room temperature. A combination of near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and CO temperature-programmed reduction (CO-TPR) shows that the high reactivity at low temperatures can be related to the improved reducibility of lattice oxygen on the CeO2 support. While single-atom catalysts (SACs) have attracted a lot of interest, the nature of the active sites in SACs remains elusive. Here the authors elucidate that depositing single atoms via high temperature synthesis leads to improved reducibility of lattice oxygen on CeO2 yielding low temperature reactivity of Pt catalysts in CO oxidation.
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92
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Rohling R, Szyja BM, Hensen EJM. Insight into the Formation of Nanostructured MFI Sheets and MEL Needles Driven by Molecular Recognition. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:5326-5335. [PMID: 30873254 PMCID: PMC6410615 DOI: 10.1021/acs.jpcc.8b08251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/03/2019] [Indexed: 06/09/2023]
Abstract
Mesoporous and nanostructured zeolite-based catalysts experience prolonged lifetimes due to increased mass transfer and reduced micropore obstruction by coke formation as compared to their bulky microporous counterparts. Diquaternary ammonium structure-directing agents (SDAs) can be used to synthesize hierarchical MFI sheet-like and MEL needle-like zeolites. An explanation of the underlying molecular-level details of the synthesis of these nanostructured zeolites is presented on the basis of non-covalent interactions between the template and zeolite surfaces as well as silicate oligomers studied by means of classical molecular dynamics. Use was made of Si11 and Si33 silicate oligomers that contain structural features of the framework to be formed as originally proposed by the Leuven group. Molecular recognition is driven by a combination of strong electrostatic and weaker dispersion interactions. An analysis of the early stage of zeolite formation is necessary, as the template adsorption energies in the fully formed zeolite crystals cannot explain the preferential growth of the MFI sheets or MEL needles. Specifically, it is found that the differences in dispersion interactions between the SDA alkyl chains and the silicate oligomers are decisive in the formation of particular zeolite structures.
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93
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Li H, Guo H, Su Y, Hiraga Y, Fang Z, Hensen EJM, Watanabe M, Smith RL. N-formyl-stabilizing quasi-catalytic species afford rapid and selective solvent-free amination of biomass-derived feedstocks. Nat Commun 2019; 10:699. [PMID: 30741927 PMCID: PMC6370847 DOI: 10.1038/s41467-019-08577-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 01/17/2019] [Indexed: 11/30/2022] Open
Abstract
Nitrogen-containing compounds, especially primary amines, are vital building blocks in nature and industry. Herein, a protocol is developed that shows in situ formed N-formyl quasi-catalytic species afford highly selective synthesis of formamides or amines with controllable levels from a variety of aldehyde- and ketone-derived platform chemical substrates under solvent-free conditions. Up to 99% yields of mono-substituted formamides are obtained in 3 min. The C-N bond formation and N-formyl species are prevalent in the cascade reaction sequence. Kinetic and isotope labeling experiments explicitly demonstrate that the C-N bond is activated for subsequent hydrogenation, in which formic acid acts as acid catalyst, hydrogen donor and as N-formyl species source that stabilize amine intermediates elucidated with density functional theory. The protocol provides access to imides from aldehydes, ketones, carboxylic acids, and mixed-substrates, requires no special catalysts, solvents or techniques and provides new avenues for amination chemistry. Processes for efficient production of primary, secondary or ternary aminated compounds are constant challenges for chemical and pharmaceutical industries. Here, the authors develop selective and sustainable amination chemistry widely applicable to chemical substrates via formic acid.
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94
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Rohling R, Tranca IC, Hensen EJM, Pidko EA. Correlations between Density-Based Bond Orders and Orbital-Based Bond Energies for Chemical Bonding Analysis. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:2843-2854. [PMID: 30842801 PMCID: PMC6394209 DOI: 10.1021/acs.jpcc.8b08934] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/19/2018] [Indexed: 05/05/2023]
Abstract
Quantum chemistry-based codes and methods provide valuable computational tools to estimate reaction energetics and elucidate reaction mechanisms. Electronic structure methods allow directly studying the chemical transformations in molecular systems involving breaking and making of chemical bonds and the associated changes in the electronic structure. The link between the electronic structure and chemical bonding can be provided through the crystal orbital Hamilton population (COHP) analysis that allows quantifying the bond strength by computing Hamilton-weighted populations of localized atomic orbitals. Another important parameter reflecting the nature and strength of a chemical bond is the bond order that can be assessed by the density derived electrostatic and chemical (DDEC6) method which relies on an electron and spin density-partitioning scheme. Herein, we describe a linear correlation that can be established between the DDEC6-derived bond orders and the bond strengths computed with the COHP formalism. We demonstrate that within defined boundaries, the COHP-derived bond strengths can be consistently compared among each other and linked to the DDEC6-derived bond orders independent of the used model. The validity of these correlations and the effective model independence of the electronic descriptors are demonstrated for a variety of gas-phase chemical systems, featuring different types of chemical bonds. Furthermore, the applicability of the derived correlations to the description of complex reaction paths in periodic systems is demonstrated by considering the zeolite-catalyzed Diels-Alder cycloaddition reaction between 2,5-dimethylfuran and ethylene.
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95
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van Oversteeg CM, Oropeza FE, Hofmann JP, Hensen EJM, de Jongh PE, de Mello Donega C. Water-Dispersible Copper Sulfide Nanocrystals via Ligand Exchange of 1-Dodecanethiol. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2019; 31:541-552. [PMID: 30686859 PMCID: PMC6345102 DOI: 10.1021/acs.chemmater.8b04614] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/18/2018] [Indexed: 05/16/2023]
Abstract
In colloidal Cu2-x S nanocrystal synthesis, thiols are often used as organic ligands and the sulfur source, as they yield high-quality nanocrystals. However, thiol ligands on Cu2-x S nanocrystals are difficult to exchange, limiting the applications of these nanocrystals in photovoltaics, biomedical sensing, and photocatalysis. Here, we present an effective and facile procedure to exchange native 1-dodecanethiol on Cu2-x S nanocrystals by 3-mercaptopropionate, 11-mercaptoundecanoate, and S2- in formamide under inert atmosphere. The product hydrophilic Cu2-x S nanocrystals have excellent colloidal stability in formamide. Furthermore, the size, shape, and optical properties of the nanocrystals are not significantly affected by the ligand exchange. Water-dispersible Cu2-x S nanocrystals are easily obtained by precipitation of the nanocrystals capped by S2-, 3-mercaptopropionate, or 11-mercaptoundecanoate from formamide, followed by redispersion in water. Interestingly, the ligand exchange rates for Cu2-x S nanocrystals capped with 1-dodecanethiol are observed to depend on the preparation method, being much slower for Cu2-x S nanocrystals prepared through heating-up than through hot-injection synthesis protocols. XPS studies reveal that the differences in the ligand exchange rates are due to the surface chemistry of the Cu2-x S nanocrystals, where the nanocrystals prepared via hot-injection synthesis have a less dense ligand layer due to the presence of trioctylphosphine oxide during synthesis. A model is proposed that explains the observed differences in the ligand exchange rates. The facile ligand exchange procedures reported here enable the use of high-quality colloidal Cu2-x S nanocrystals prepared in the presence of 1-dodecanethiol in various applications.
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96
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Rohling R, Tranca IC, Hensen EJM, Pidko EA. Mechanistic Insight into the [4 + 2] Diels-Alder Cycloaddition over First Row d-Block Cation-Exchanged Faujasites. ACS Catal 2019; 9:376-391. [PMID: 30775064 PMCID: PMC6369662 DOI: 10.1021/acscatal.8b03482] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/18/2018] [Indexed: 01/07/2023]
Abstract
The Diels-Alder cycloaddition (DAC) is a powerful tool to construct C-C bonds. The DAC reaction can be accelerated in several ways, one of which is reactant confinement as observed in supramolecular complexes and Diels-Alderases. Another method is altering the frontier molecular orbitals (FMOs) of the reactants by using homogeneous transition-metal complexes whose active sites exhibit d-orbitals suitable for net-bonding orbital interactions with the substrates. Both features can be combined in first row d-block (TM) exchanged faujasite catalysts where the zeolite framework acts as a stabilizing ligand for the active site while confining the reactants. Herein, we report on a mechanistic and periodic DFT study on TM-(Cu(I), Cu(II), Zn(II), Ni(II), Cr(III), Sc(III), V(V))exchanged faujasites to elucidate the effect of d-shell filling on the DAC reaction between 2,5-dimethylfuran and ethylene. Two pathways were found: one being the concerted one-step and the other being the stepwise two-step pathway. A decrease in d-shell filling results in a concomitant increase in reactant activation as evidenced by increasingly narrow energy gaps and lower activation barriers. For models holding relatively small d-block cations, the zeolite framework was found to bias the DAC reaction toward an asynchronous one-step pathway instead of the two-step pathway. This work is an example of how the active site properties and the surrounding chemical environment influence the reaction mechanism of chemical transformations.
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97
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Vrijburg WL, van Helden JWA, Parastaev A, Groeneveld E, Pidko EA, Hensen EJM. Ceria–zirconia encapsulated Ni nanoparticles for CO 2 methanation. Catal Sci Technol 2019. [DOI: 10.1039/c9cy01428d] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Preparing Ni catalysts on ceria–zirconia via colloidal Ni nanoparticle encapsulation yields excellent particle size control, superior catalytic activity, and enhanced stability compared to conventional impregnation techniques.
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98
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Wu L, van Hoof AJF, Dzade NY, Gao L, Richard MI, Friedrich H, De Leeuw NH, Hensen EJM, Hofmann JP. Enhancing the electrocatalytic activity of 2H-WS2 for hydrogen evolution via defect engineering. Phys Chem Chem Phys 2019; 21:6071-6079. [DOI: 10.1039/c9cp00722a] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Introduction of defects into 2H-WS2 electrocatalysts by post-synthetic desulfurization leads to significantly improved H2 evolution activity.
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99
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Bolshakov A, Kosinov N, Romero Hidalgo DE, Mezari B, van Hoof AJF, Hensen EJM. Mild dealumination of template-stabilized zeolites by NH4F. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00593e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A novel method to remove aluminium from the framework of as-synthesized zeolite crystals is presented.
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100
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Vrijburg WL, van Helden JWA, van Hoof AJF, Friedrich H, Groeneveld E, Pidko EA, Hensen EJM. Tunable colloidal Ni nanoparticles confined and redistributed in mesoporous silica for CO2 methanation. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00532c] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Colloidal Ni nanoparticles were prepared using seed-mediated strategies and encapsulated in mesoporous silica to yield stable and sinter-resistant hydrogenation catalysts.
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