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Lu S, Xu P, Cao X, Gu H. A highly active worm-like PtMo nanowire for the selective synthesis of dibenzylamines. RSC Adv 2018; 8:8755-8760. [PMID: 35539856 PMCID: PMC9078585 DOI: 10.1039/c8ra00787j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 02/13/2018] [Indexed: 11/21/2022] Open
Abstract
Worm-like nanowires are among the most active nanomaterials. In this study, we report the synthesis of dibenzylamine (DBA) motifs from reductive amination of either aldehydes or nitriles catalyzed by entirely new worm-like PtMo nanowires (PtMo WNWs). Under the assistance of H2 gas, PtMo WNWs can be prepared in a facile manner, following which, their structure and composition are characterized by TEM, XRD, XPS, etc. Upon careful optimization of reaction parameters, the as-prepared PtMo WNWs work effectively in the activation of dihydrogen molecules, and both aldehydes and nitriles can be used as starting materials to fabricate DBAs under mild and green conditions. The reaction kinetics has been investigated, which reveals that the PtMo WNWs show superior activity in the conversion of imines into amines. This study provides a practical advancement in the preparation of amines. Moreover, the protocol reported herein is feasible for the synthesis of worm-like nanostructures with designed composition for various catalytic applications. An efficient synthetic pathway of dibenzylamine (DBA) motifs from reductive amination of either aldehydes or nitriles catalyzed by highly active worm-like PtMo nanowires.![]()
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Affiliation(s)
- Shuanglong Lu
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry, Chemical Engineering and Materials Science
- Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
| | - Pengyao Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry, Chemical Engineering and Materials Science
- Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
| | - Xueqin Cao
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry, Chemical Engineering and Materials Science
- Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
| | - Hongwei Gu
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry, Chemical Engineering and Materials Science
- Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
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Cai JQ, Luo HJ, Tao XM, Tan MQ. Initial Subsurface Incorporation of Oxygen into Ru(0001): A Density Functional Theory Study. Chemphyschem 2015; 16:3937-48. [DOI: 10.1002/cphc.201500681] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/02/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Jian-Qiu Cai
- Department of Physics; Zhejiang University; No. 38 Zheda Road Hangzhou 310027 China
- College of Physics and Electronic Information Engineering; Wenzhou University, Chashan Higher Education Park; Wenzhou 325035 China
| | - Hai-Jun Luo
- Department of Physics; Zhejiang University; No. 38 Zheda Road Hangzhou 310027 China
- College of Physics and Electronic Information Engineering; Wenzhou University, Chashan Higher Education Park; Wenzhou 325035 China
| | - Xiang-Ming Tao
- Department of Physics; Zhejiang University; No. 38 Zheda Road Hangzhou 310027 China
| | - Ming-Qiu Tan
- Department of Physics; Zhejiang University; No. 38 Zheda Road Hangzhou 310027 China
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Sun X, Jiang K, Zhang N, Guo S, Huang X. Crystalline Control of {111} Bounded Pt3Cu Nanocrystals: Multiply-Twinned Pt3Cu Icosahedra with Enhanced Electrocatalytic Properties. ACS NANO 2015; 9:7634-7640. [PMID: 26172056 DOI: 10.1021/acsnano.5b02986] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Despite that different facets have distinct catalytic behavior, the important role of twin defects on enhancing the catalytic performance of metallic nanocrystals is largely unrevealed. The key challenge in demonstrating the importance of twin defects for catalysis is the extreme difficulties in creating nanostructures with the same exposed facets but tunable twin defects that are suitable for catalytic investigations. Herein, we show an efficient synthetic strategy to selectively synthesize {111}-terminated Pt3Cu nanocrystals with controllable crystalline features. Two distinct {111}-bounded shapes, namely, multiply-twinned Pt3Cu icosahedra and single-crystalline Pt3Cu octahedra, are successfully prepared by simply changing the types of Cu precursors with the other growth parameters unchanged. Electrocatalytic studies show that the {111}-terminated Pt3Cu nanocrystals exhibit the very interesting crystalline nature-dependent electrocatalytic activities toward both the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) with multiply-twinned Pt3Cu icosahedra demonstrating enhanced electrocatalytic activities compared to the single-crystalline Pt3Cu octahedra due to their additional yet important effect of twin defect. As a result, under the multiple tuning conditions (alloy, shape, and twin effects), the multiply-twinned Pt3Cu icosahedra exhibit much enhanced electrocatalytic activities in both ORR and MOR with respect to the Pt black. The present work highlights the importance of twin defects in enhancing electrocatalytic activities of metallic nanocrystals.
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Affiliation(s)
- Xiuhui Sun
- †College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Kezhu Jiang
- †College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Nan Zhang
- †College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Shaojun Guo
- ‡Physical Chemistry and Applied Spectroscopy, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Xiaoqing Huang
- †College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
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Huang X, Zhao Z, Chen Y, Chiu CY, Ruan L, Liu Y, Li M, Duan X, Huang Y. High density catalytic hot spots in ultrafine wavy nanowires. NANO LETTERS 2014; 14:3887-94. [PMID: 24873775 DOI: 10.1021/nl501137a] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Structural defects/grain boundaries in metallic materials can exhibit unusual chemical reactivity and play important roles in catalysis. Bulk polycrystalline materials possess many structural defects, which is, however, usually inaccessible to solution reactants and hardly useful for practical catalytic reactions. Typical metallic nanocrystals usually exhibit well-defined crystalline structure with few defects/grain boundaries. Here, we report the design of ultrafine wavy nanowires (WNWs) with a high density of accessible structural defects/grain boundaries as highly active catalytic hot spots. We show that rhodium WNWs can be readily synthesized with controllable number of structural defects and demonstrate the number of structural defects can fundamentally determine their catalytic activity in selective oxidation of benzyl alcohol by O2, with the catalytic activity increasing with the number of structural defects. X-ray photoelectron spectroscopy (XPS) and cyclic voltammograms (CVs) studies demonstrate that the structural defects can significantly alter the chemical state of the Rh WNWs to modulate their catalytic activity. Lastly, our systematic studies further demonstrate that the concept of defect engineering in WNWs for improved catalytic performance is general and can be readily extended to other similar systems, including palladium and iridium WNWs.
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Affiliation(s)
- Xiaoqing Huang
- Department of Materials Science and Engineering, University of California , Los Angeles, California 90095, United States
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Lu J, Neto AC, Loh KP. Transforming moiré blisters into geometric graphene nano-bubbles. Nat Commun 2012; 3:823. [DOI: 10.1038/ncomms1818] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Accepted: 04/02/2012] [Indexed: 12/23/2022] Open
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Rosenthal D, Girgsdies F, Timpe O, Blume R, Weinberg G, Teschner D, Schlögl R. On the CO-Oxidation over Oxygenated Ruthenium. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2009.6032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The oxidation of carbon monoxide over polycrystalline ruthenium dioxide (RuO2) powder was studied in a packed-bed reactor and by bulk and surface analytical methods. Activity data were correlated with bulk phases in an in-situ X-ray diffraction (XRD) setup at atmospheric pressure. Ruthenium dioxide was pre-calcined in pure oxygen at 1073 K. At this stage RuO2 is completely inactive in the oxidation of CO. After a long induction period in the feed at 503 K RuO2 becomes active with 100% conversion, while in-situ XRD reveals no changes in the RuO2 diffraction pattern. At this stage selective roughening of apical RuO2 facets was observed by scanning electron microscopy (SEM). Seldom also single lateral facets are roughened. EDX indicated higher oxygen content in the following order: flat lateral facets > rough lateral facets > rough apical facets. Further, experiments in the packed bed reactor indicated oscillations in the CO2 formation rate. At even higher temperatures in reducing feed (533–543 K) the sample reduces to ruthenium metal according to XRD. The reduced particles exhibiting lower ignition temperature are very rough with cracks and deep star-shaped holes. An Arrhenius plot of the CO2 formation rate below the ignition temperature reveals the reduced samples to be significantly more active based on mass unit and shows lower apparent activation energy than the activated oxidized sample. Micro-spot X-ray photoelectron spectroscopy (XPS) and XPS microscopy experiments were carried out on a Ru(0001) single crystal exposed to oxygen at different temperature. Although low energy electron diffraction (LEED) images show a strong 1×1 pattern, the XPS data indicated a wide lateral inhomogeneity with different degree of oxygen dissolved in the subsurface layers. All these and the literature data are discussed in the context of different active states and transport issues, and the metastable nature of a phase mixture under conditions of high catalytic activity.
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Affiliation(s)
| | - Frank Girgsdies
- Fritz-Haber-Institute of the MPG, Department of Inorganic Chemistry, Berlin, Deutschland
| | - Olaf Timpe
- Fritz-Haber-Institute of the MPG, Department of Inorganic Chemistry, Berlin, Deutschland
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Knop‐Gericke A, Kleimenov E, Hävecker M, Blume R, Teschner D, Zafeiratos S, Schlögl R, Bukhtiyarov VI, Kaichev VV, Prosvirin IP, Nizovskii AI, Bluhm H, Barinov A, Dudin P, Kiskinova M. Chapter 4 X‐Ray Photoelectron Spectroscopy for Investigation of Heterogeneous Catalytic Processes. ADVANCES IN CATALYSIS 2009. [DOI: 10.1016/s0360-0564(08)00004-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Oxidation of methanol on Ru catalyst: Effect of the reagents partial pressures on the catalyst oxidation state and selectivity. Catal Today 2007. [DOI: 10.1016/j.cattod.2007.02.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Blume R, Christen W, Niehus H. Reactivity of Oxide Precursor States on Ru(0001). J Phys Chem B 2006; 110:13912-9. [PMID: 16836341 DOI: 10.1021/jp061937a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Smooth and defect-rich Ru(0001) surfaces prepared under ultrahigh-vacuum (UHV) conditions have been loaded with oxygen under high-pressure (p </= 1 bar) and low-temperature (T < 550 K) conditions. On these surfaces the CO oxidation reaction has been investigated by means of thermal desorption spectroscopy (TDS), ultraviolet photoelectron spectroscopy (UPS) and reactive molecular beam scattering (RMBS). Both surfaces are oxide-free and exhibit a high reactivity. The maximum CO/CO(2) conversion probability observed for a defect-rich Ru(0001) surface amounts to 6 x 10(-3) and is comparable to that of a surface covered with rutile RuO(2)(110) domains. RMBS experiments led to the identification of three different reaction channels. The first and second channel is related to CO adsorbing at oxygen-free defect sites and follow the Langmuir-Hinshelwood mechanism. Whereas the first reaction channel is already observed at room temperature, the second is thermally activated, contributing to the CO(2) yield only for reaction temperatures above 400 K. The third channel is due to the recombination of CO molecules with oxygen atoms located in smooth areas of the surface undisturbed by defects. This reaction channel is thermally activated as well.
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Affiliation(s)
- Raoul Blume
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany.
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Nieskens DLS, Curulla-Ferré D, Niemantsverdriet JW. Migration of Carbon into Subsurface Layers of Rh(100): A DFT Study. Chemphyschem 2006; 7:1022-5. [PMID: 16596694 DOI: 10.1002/cphc.200500553] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Davy L S Nieskens
- Schuit Institute of Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Einhoven, The Netherlands.
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Blume R, Niehus H, Conrad H, Böttcher A, Aballe L, Gregoratti L, Barinov A, Kiskinova M. Identification of Subsurface Oxygen Species Created during Oxidation of Ru(0001). J Phys Chem B 2005; 109:14052-8. [PMID: 16852764 DOI: 10.1021/jp044175x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxidation states formed during low-temperature oxidation (T < 500 K) of a Ru(0001) surface are identified with photoelectron spectromicroscopy and thermal desorption (TD) spectroscopy. Adsorption and consecutive incorporation of oxygen are studied following the distinct chemical shifts of the Ru 3d(5/2) core levels of the two topmost Ru layers. The evolution of the Ru 3d(5/2) spectra with oxygen exposure at 475 K and the corresponding O2 desorption spectra reveal that about 2 ML of oxygen incorporate into the subsurface region, residing between the first and second Ru layer. Our results suggest that the subsurface oxygen binds to the first and second layer Ru atoms, yielding a metastable surface "oxide", which represents the oxidation state of an atomically well ordered Ru(0001) surface under low-temperature oxidation conditions. Accumulation of more than 3 ML of oxygen is possible via defect-promoted penetration below the second layer when the initial Ru(0001) surface is disordered. Despite its higher capacity for oxygen accumulation, also the disordered Ru surface does not show features characteristic for the crystalline RuO2 islands. Development of lateral heterogeneity in the oxygen concentration is evidenced by the Ru 3d(5/2) images and microspot spectra after the onset of oxygen incorporation, which becomes very pronounced when the oxidation is carried out at T > 550 K. This is attributed to facilitated O incorporation and oxide nucleation in microregions with a high density of defects.
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Affiliation(s)
- Raoul Blume
- Institut für Physik der Humboldt-Universität, Newtonstrasse 15, 12489 Berlin, Germany.
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