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He W, Zhang X, Zheng K, Wu C, Pan Y, Li H, Xu L, Xu R, Chen W, Liu Y, Wang C, Sun Z, Wei S. Structural Evolution of Anatase-Supported Platinum Nanoclusters into a Platinum-Titanium Intermetallic Containing Platinum Single Atoms for Enhanced Catalytic CO Oxidation. Angew Chem Int Ed Engl 2023; 62:e202213365. [PMID: 36396598 DOI: 10.1002/anie.202213365] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Indexed: 11/19/2022]
Abstract
Strong metal-support interactions characteristic of the encapsulation of metal particles by oxide overlayers have been widely observed on large metal nanoparticles, but scarcely occur on small nanoclusters (<2 nm) for which the metal-support interactions remain elusive. Herein, we study the structural evolution of Pt nanoclusters (1.5 nm) supported on anatase TiO2 upon high-temperature H2 reduction. The Pt nanoclusters start to partially evolve into a CsCl-type PtTi intermetallic compound when the reduction temperature reaches 400 °C. Upon 700 °C reduction, the PtTi nanoparticles are exclusively formed and grow epitaxially along the TiO2 (101) crystal faces. The thermodynamics of the formation of PtTi via migration of reduced Ti atoms into Pt cluster is unraveled by theoretical calculations. The thermally stable PtTi intermetallic compound, with single-atom Pt isolated by Ti, exhibits enhanced catalytic activity and promoted catalytic durability for CO oxidation.
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Affiliation(s)
- Wenxue He
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Xu Zhang
- Beijing Key Lab of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Kun Zheng
- Beijing Key Lab of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Chuanqiang Wu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Ya Pan
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Hongmei Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Liuxin Xu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Ruichao Xu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Wei Chen
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Yi Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Chao Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Zhihu Sun
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
| | - Shiqiang Wei
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, P. R. China
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2
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Sadykov II, Sushkevich VL, Krumeich F, Nuguid RJG, van Bokhoven JA, Nachtegaal M, Safonova OV. Platinum-Iron(II) Oxide Sites Directly Responsible for Preferential Carbon Monoxide Oxidation at Ambient Temperature: An Operando X-ray Absorption Spectroscopy Study. Angew Chem Int Ed Engl 2023; 62:e202214032. [PMID: 36349828 DOI: 10.1002/anie.202214032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Indexed: 11/11/2022]
Abstract
Operando X-ray absorption spectroscopy identified that the concentration of Fe2+ species in the working state-of-the-art Pt-FeOx catalysts quantitatively correlates to their preferential carbon monoxide oxidation steady-state reaction rate at ambient temperature. Deactivation of such catalysts with time on stream originates from irreversible oxidation of active Fe2+ sites. The active Fe2+ species are presumably Fe+2 O-2 clusters in contact with platinum nanoparticles; they coexist with spectator trivalent oxidic iron (Fe3+ ) and metallic iron (Fe0 ) partially alloyed with platinum. The concentration of active sites and, therefore, the catalyst activity strongly depends on the pretreatment conditions. Fe2+ is the resting state of the active sites in the preferential carbon monoxide oxidation cycle.
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Affiliation(s)
- Ilia I Sadykov
- Energy and Environment Research Division, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland.,Institute for Chemical and Bioengineering, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093, Zürich, Switzerland
| | - Vitaly L Sushkevich
- Energy and Environment Research Division, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Frank Krumeich
- Institute for Chemical and Bioengineering, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093, Zürich, Switzerland
| | - Rob Jeremiah G Nuguid
- Energy and Environment Research Division, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Jeroen A van Bokhoven
- Energy and Environment Research Division, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland.,Institute for Chemical and Bioengineering, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093, Zürich, Switzerland
| | - Maarten Nachtegaal
- Energy and Environment Research Division, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Olga V Safonova
- Energy and Environment Research Division, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland
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3
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Fabrication of Pt/Co3O4 nanocatalysts based on pollen template for low-temperature CO oxidation. CATAL COMMUN 2022. [DOI: 10.1016/j.catcom.2022.106597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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4
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Han B, Li X, Geng Z, Li L, Li G. Confinement chemistry of FeO x centers for activating molecular oxygen under ambient conditions. NANOSCALE 2022; 14:9715-9723. [PMID: 35730888 DOI: 10.1039/d2nr02236b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Activating molecular oxygen under mild conditions is highly important for developing advanced green technologies and for understanding the origin and running of life as well, which still remains a challenge. In this work, we report on the confinement chemistry for activating molecular oxygen over oxides under mild conditions by presenting the synthesis and characterization of FeOx species confined to the pores of support CeO2 nanospheres. Active catalytic materials are obtained by a controllable three-step method via the formation of porous CeO2 nanospheres that have an average diameter of 120 nm and exhibit a large surface area of 168 m2 g-1 and a pore size of 18.7 nm, confining FeOx in intimate contact with ultra-small Pt particles in pores. The optimized PtOy-FeOx/CeO2-H catalyst showed an excellent performance in the preferential oxidation of CO reactions, as featured by 100% CO conversion at room temperature with almost no attenuation in a prolonged operation, which could not be accessible without pore-confined FeOx centers. Mechanical studies prove that the reaction progresses via abnormal non-competitive adsorption associated with synergistic roles from uniform loading, stabilization of divalent Fe species, surface oxygen activation on CeO2 supports, and the reduced H2 spillover effect on Pt0, making the CO species adsorbed on Ptδ+ easier to be desorbed. The methodology demonstrated here may inspire one to explore more advanced catalysts with high activity at room temperature essential for a wide range of applications.
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Affiliation(s)
- Bingqi Han
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
| | - Xinbo Li
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
| | - Zhibin Geng
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
| | - Liping Li
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
| | - Guangshe Li
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
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5
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Zheng B, Duan J, Tang Q. Electronic metal-support interaction constructed for preparing sinter-resistant nano-platinum catalyst with redox property. Dalton Trans 2022; 51:7491-7502. [PMID: 35506442 DOI: 10.1039/d1dt04142h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Generally, support materials with particular structural properties could effectively anchor metal nanoparticles and provide lower activation barriers in heterogeneous catalysis. To tailor the structure of stable iron oxide, NiFe2O4 of inverse spinel structure was obtained by combining nickel with iron element under an alkaline environment and high-temperature calcination. The p-type conductivity of NiFe2O4 provides the possibility of constructing electronic interfacial interaction with Pt nanoparticles by electron transfer. The constructed metal-support interaction could effectively stabilize Pt nanoparticles and be further enhanced during long-term harsh calcination (700 °C for 48 h) even under an O2 atmosphere. Meanwhile, the abundant structural defects of NiFe2O4 are beneficial for constructing low-temperature redox centers with the aid of Pt nanoparticles. Pt/NiFe2O4 exhibited not only excellent activity in room-temperature oxidation (CO and HCHO) and reduction reactions (chemo-selective hydrogenation of nitroarenes), but also high stability even after storage for more than 6 months. A self-adjusting mechanism triggered by structural defects is disclosed by in situ characterization and systematic reaction results. This work demonstrates an alternative concept to construct sinter-resistant and highly-effective nano-platinum catalysts robust for oxidation and reduction reactions.
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Affiliation(s)
- Bin Zheng
- Institute of New Energy Technology, College of Information Science and Technology, Jinan University, Guangzhou, 510632, P. R. China. .,School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, 252000, P. R. China
| | - Jialong Duan
- Institute of New Energy Technology, College of Information Science and Technology, Jinan University, Guangzhou, 510632, P. R. China.
| | - Qunwei Tang
- Institute of New Energy Technology, College of Information Science and Technology, Jinan University, Guangzhou, 510632, P. R. China.
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Jiang B, Cha X, Huang Z, Hu S, Xu K, Cai D, Xiao J, Zhan G. Green fabrication of hierarchically-structured Pt/bio-CeO2 nanocatalysts using natural pollen templates for low-temperature CO oxidation. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112251] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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7
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Promotion Effect of the Keggin Structure on the Sulfur and Water Resistance of Pt/CeTi Catalysts for CO Oxidation. Catalysts 2021. [DOI: 10.3390/catal12010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Developing a catalyst with high SO2 and H2O resistance to achieve high-performance CO oxidation for specific industrial applications is highly desirable. Here, three catalysts were prepared using cerium titanium composite oxide (CeTi), molybdophosphate with Keggin structure-modified CeTi (Keg-CeTi), and molybdophosphate without Keggin structure-modified CeTi (MoP-CeTi) as supports, and their sulfur and water resistance in CO oxidation were tested. The characterization of XRD, BET, SO2/H2O-DRIFTS, XPS, TEM, SEM, NH3/SO2-TPD, H2-TPR, and ICP techniques revealed that the high SO2 and H2O resistance of Pt/Keg-CeTi in CO oxidation was related to its stronger surface acidity, better reduction of surface cerium and molybdenum species, and lower SO2 adsorption and transformation compared to Pt/CeTi and Pt/MoP-CeTi.
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8
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High Catalytic Activity of Pt/Al2O3 Catalyst in CO Oxidation at Room Temperature—A New Insight into Strong Metal–Support Interactions. Catalysts 2021. [DOI: 10.3390/catal11121475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The concept of very strong metal–support interactions (VSMSI) was defined in regard to the interactions that influence the catalytic properties of catalysts due to the creation of a new phase as a result of a solid-state chemical reaction between the metal and support. In this context, the high catalytic activity of the 1%Pt/Al2O3 catalyst in the CO oxidation reaction at room temperature was explained. The catalyst samples were reduced at different temperatures ranging from 500 °C to 800 °C and characterized using TPR, O2/H2 titration, CO chemisorption, TPD-CO, FTIR-CO, XRD, and TOF-SIMS methods. Based on the obtained results, it was claimed that with very high temperature reduction (800 °C), nonstoichiometric platinum species [Pt(Cl)Ox] strongly anchored to Al2O3 surface are formed. These species act as the oxygen adsorption sites.
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Sadykov II, Zabilskiy M, Clark AH, Krumeich F, Sushkevich V, van Bokhoven JA, Nachtegaal M, Safonova OV. Time-Resolved XAS Provides Direct Evidence for Oxygen Activation on Cationic Iron in a Bimetallic Pt-FeO x/Al 2O 3 Catalyst. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilia I. Sadykov
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland
| | | | - Adam H. Clark
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Frank Krumeich
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Vitaly Sushkevich
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Jeroen A. van Bokhoven
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland
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10
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Lin A, Ming C, Sun YY. Dilute Element Compounds: A Route to Enriching Inorganic Functional Materials. J Phys Chem Lett 2021; 12:8194-8202. [PMID: 34415168 DOI: 10.1021/acs.jpclett.1c02490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The development of functional materials calls for ever-enriching the inorganic material database. Doping is an effective way of achieving this purpose. Herein, we propose the concept of dilute element compounds (DECs), which contain a small amount of a dopant element distributed in a host crystal structure in an ordered manner. Different from dilute alloys or solid solutions, the DECs could be more resistant to segregation and are ideal for dispersing functional elements for applications such as single-atom catalysts. It is also expected that the DECs will serve as a route to discovering new inorganic functional materials by controlling phase transitions and tuning intrinsic properties of the host materials with applications including, but not limited to, thermoelectrics and solid-state electrolytes for secondary batteries. As an initial work, we quantify the diluteness of DECs and find the limits of diluteness in existing DECs. We further provide a classification scheme for the DECs to guide future discoveries.
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Affiliation(s)
- Aming Lin
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Ming
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
| | - Yi-Yang Sun
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Zheng B, Gan T, Shi S, Wang J, Zhang W, Zhou X, Zou Y, Yan W, Liu G. Exsolution of Iron Oxide on LaFeO 3 Perovskite: A Robust Heterostructured Support for Constructing Self-Adjustable Pt-Based Room-Temperature CO Oxidation Catalysts. ACS APPLIED MATERIALS & INTERFACES 2021; 13:27029-27040. [PMID: 34096275 DOI: 10.1021/acsami.1c04836] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Constructing highly active and stable surface sites for O2 activation is essential to lower the barrier of Pt-based catalysts for CO oxidation. Although a few active Pt-metal oxide interfaces have been reported, questions about the stability of these sites under the long-term storage and operation remain unresolved. Here, based on developing a robust FeOx/LaFeO3 heterostructure as a support, we constructed stable Pt-support interfaces to achieve highly active CO oxidation at room temperature. Even after it is kept in the air for more than 6 months, the catalyst (without pretreatment) still maintains the high activity like a fresh one, which is superior to metal hydroxide-Pt interfaces, and meets the requirements of long-term storage for emergency use. In situ characterizations and systematic reaction results showed that CO oxidation occurs through an alternative mechanism, which is triggered by intrinsic reactants and self-adjusted to a more active interface in the reaction process. Theoretical calculations and 57Fe Mössbauer spectra revealed that abundant cation vacancies significantly increase the activity of surface oxygen species and should be responsible for this unique process. This work demonstrates an alternative concept to fabricate robust and highly active Pt-based catalysts for catalytic oxidation.
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Affiliation(s)
- Bin Zheng
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
| | - Tao Gan
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
| | - Shaozhen Shi
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
| | - Junhu Wang
- Mössbauer Effect Data Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning, China
| | - Wenxiang Zhang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
| | - Xin Zhou
- College of Environment and Chemical Engineering, Dalian University, 10 Xuefu Road, Dalian 116622, Liaoning, China
| | - Yongcun Zou
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
| | - Wenfu Yan
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
| | - Gang Liu
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Road, Changchun 130012, Jilin, China
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12
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Electron donation of non-oxide supports boosts O 2 activation on nano-platinum catalysts. Nat Commun 2021; 12:2741. [PMID: 33980837 PMCID: PMC8115247 DOI: 10.1038/s41467-021-22946-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/29/2021] [Indexed: 11/08/2022] Open
Abstract
Activation of O2 is a critical step in heterogeneous catalytic oxidation. Here, the concept of increased electron donors induced by nitrogen vacancy is adopted to propose an efficient strategy to develop highly active and stable catalysts for molecular O2 activation. Carbon nitride with nitrogen vacancies is prepared to serve as a support as well as electron sink to construct a synergistic catalyst with Pt nanoparticles. Extensive characterizations combined with the first-principles calculations reveal that nitrogen vacancies with excess electrons could effectively stabilize metallic Pt nanoparticles by strong p-d coupling. The Pt atoms and the dangling carbon atoms surround the vacancy can synergistically donate electrons to the antibonding orbital of the adsorbed O2. This synergistic catalyst shows great enhancement of catalytic performance and durability in toluene oxidation. The introduction of electron-rich non-oxide substrate is an innovative strategy to develop active Pt-based oxidation catalysts, which could be conceivably extended to a variety of metal-based catalysts for catalytic oxidation. Activation of O2 is a critical step in heterogeneous catalytic oxidation. Here, the authors adopt the concept of increased electron donors induced by nitrogen vacancy to develop an efficient strategy for preparing highly active and stable catalysts for molecular O2 activation.
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He W, Huang L, Liu C, Wang S, Long Z, Hu F, Sun Z. Interfacial sites in platinum-hydroxide-cobalt hybrid nanostructures for promoting CO oxidation activity. NANOSCALE 2021; 13:2593-2600. [PMID: 33480944 DOI: 10.1039/d0nr07880h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Metal-oxide/hydroxide hybrid nanostructures provide an excellent platform to study the interfacial effects on tailoring the catalysis of metal catalysts. Herein, a hybrid nanostructure of Pt@Co(OH)2 supported on SiO2 was synthesized by incipient wetness impregnation of Co(OH)2 with the aid of H2O2 and successive urea-assisted deposition-precipitation of platinum nanoparticles. The Fenton-like reaction between Co2+ and H2O2 during the impregnation process facilitates the formation of active interfacial sites. This hybrid nanostructure exhibits much higher catalytic activity towards CO oxidation than Pt/SiO2 nanoparticles with a similar Pt loading and particle size. In situ diffuse reflectance infrared Fourier transform spectroscopy was used to track the CO adsorption processes and to identify the reaction intermediates during CO oxidation. It shows that the OH species at the Pt-OH-Co interfacial sites could readily react with CO adsorbed on neighboring Pt to yield CO2 by forming *COOH intermediates and oxygen vacancies. Under the CO + O2 oxidation conditions, O2 molecules are activated by the oxygen vacancy and react with the CO molecules adsorbed on Pt to generate CO2, via forming the highly active *OOH intermediates as observed by DRIFTS.
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Affiliation(s)
- Wenxue He
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
| | - Li Huang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
| | - Chengyong Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
| | - Siyu Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
| | - Zhixin Long
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
| | - Fengchun Hu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
| | - Zhihu Sun
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China.
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14
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Walsh AG, Zhang P. Thiolate-Protected Bimetallic Nanoclusters: Understanding the Relationship between Electronic and Catalytic Properties. J Phys Chem Lett 2021; 12:257-275. [PMID: 33332974 DOI: 10.1021/acs.jpclett.0c03252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Thiolate-protected metal nanoclusters, which are smaller than 2 nm and have a specific number of metal atoms, have been greatly investigated in areas such as catalysis, sensing, and energy conversion because of their unique chemical, optical, structural, and electronic properties. Doping monometallic nanoclusters with another metal offers the opportunity to enhance these properties even further. The atomic structure of thiolate-protected bimetallic nanoclusters has been thoroughly studied using various X-ray methods, but the electronic structures of these complexes are often under-discussed. This Perspective summarizes works examining the electronic properties (charge states and energy levels) of these materials using density functional theory, square-wave voltammetry, UV-vis spectroscopy, and X-ray photoelectron spectroscopy. This information is then related to the catalytic activities of these complexes in various representative reactions (e.g., carbon-carbon coupling, hydrogenation, and oxidation). The significance of the structure-property relationship between the electronic properties and the catalytic performance of thiolate-protected bimetallic nanoclusters is demonstrated.
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Affiliation(s)
- Andrew G Walsh
- Department of Chemistry, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - Peng Zhang
- Department of Chemistry, Dalhousie University, Halifax, NS, Canada B3H 4R2
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15
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Zhang T, Chen Z, Walsh AG, Li Y, Zhang P. Single-Atom Catalysts Supported by Crystalline Porous Materials: Views from the Inside. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002910. [PMID: 32656812 DOI: 10.1002/adma.202002910] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/24/2020] [Indexed: 06/11/2023]
Abstract
Single-atom catalysts (SACs) have recently emerged as an exciting system in heterogeneous catalysis showing outstanding performance in many catalytic reactions. Single-atom catalytic sites alone are not stable and thus require stabilization from substrates. Crystalline porous materials such as zeolites and metal-organic frameworks (MOFs) are excellent substrates for SACs, offering high stability with the potential to further enhance their performance due to synergistic effects. This review features recent work on the structure, electronic, and catalytic properties of zeolite and MOF-protected SACs, offering atomic-scale views from the "inside" thanks to the subatomic resolution of synchrotron X-ray absorption spectroscopy (XAS). The extended X-ray absorption fine structure and associated methods will be shown to be powerful tools in identifying the single-atom site and can provide details into the coordination environment and bonding disorder of SACs. The X-ray absorption near-edge structure will be demonstrated as a valuable method in probing the electronic properties of SACs by analyzing the white line intensity, absorption edge shift, and pre-/postedge features. Emphasis is also placed on in situ/operando XAS using state-of-the-art equipment, which can unveil the changes in structure and properties of SACs during the dynamic catalytic processes in a highly sensitive and time-resolved manner.
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Affiliation(s)
- Tianjun Zhang
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China
| | - Ziyi Chen
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Andrew G Walsh
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Yi Li
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China
- International Center of Future Science, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China
| | - Peng Zhang
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
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