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First-Principles Study of Stability and N2 Activation on the Octahedron RuRh Clusters. Catalysts 2022. [DOI: 10.3390/catal12080881] [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
The geometric and electronic structures of different octahedron RuRh clusters are studied using density functional theory calculations. The binding energy, electronic structure, and energy gap of the clusters have been obtained to determine the possible stable structures. The results show that the Ru4Rh2 cluster is the most stable structure which has D4h symmetry with the largest ionization potential, smallest affinity energy and larger energy gap. Furthermore, the information on adsorption and dissociation of multiple nitrogen molecules and the density of state for the octahedral Ru4Rh2 cluster is analyzed. The dissociation barrier of three nitrogen molecules further decreases to 1.18 eV with an increase in the number of N2 molecules. The co-adsorption of multiple N2 molecules facilitates the dissociation of N2 on the Ru4Rh2 cluster. The strong interaction between the antibonding orbital of N2 and the d orbital of the Ru4Rh2 cluster is illustrated by calculating and analyzing the results of PDOS, which stretches the N−N bond length and reduces the activation energy to dissociation. The antibonding orbital of the nitrogen molecule shows distinct and unique catalytic activity for the dissociation of the adsorbed nitrogen molecule on the octahedral Ru4Rh2 cluster.
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He X, Walter M, Jiang DE. Understanding Superatomic Ag Nanohydrides. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2004808. [PMID: 33448154 DOI: 10.1002/smll.202004808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/24/2020] [Indexed: 06/12/2023]
Abstract
Bulk Ag hydrides are extremely challenging to make even at very high pressures, but they may become stable as the particle size shrinks to the nanometer regime. Here, the formation and electronic structure of Ag nanohydrides are investigated from a superatomic perspective by density functional theory. It is found that as the coverage increases, adsorption energy of hydrogen atoms on Ag38 cluster to form Ag38 H2 n nanohydride (n is from 1 to 15) can be energetically favorable with respect to bare Ag38 and H2 . Furthermore, the adsorbed hydrogen atoms contribute their 1s electrons to the superatom electron count and behave as a metal instead of a ligand. The electronic structure of the silver nanohydrides follows the superatomic complex model, leading to magic or relatively more stable compositions such as Ag38 H2 , Ag38 H20 , and Ag38 H30 , which correspond to 40-electron, 58-electron, and 68-electron shell closings, respectively. Angular momentum analyses of the superatomic orbitals suggest a convoluted interaction of geometry, symmetry, and orbital splitting.
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Affiliation(s)
- Xiang He
- Department of Chemistry, University of California, Riverside, CA, 92521, USA
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, Jiangsu, 210008, China
| | - Michael Walter
- FIT Freiburg Centre for Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, Freiburg, 79110, Germany
| | - De-En Jiang
- Department of Chemistry, University of California, Riverside, CA, 92521, USA
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Choi J, Kwon S, Park Y, Kang K, Lee HM. In Silico High-Throughput Screening of Ag-Based Electrocatalysts for Anion-Exchange Membrane Fuel Cells. J Phys Chem Lett 2021; 12:5660-5667. [PMID: 34114817 DOI: 10.1021/acs.jpclett.1c01084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The alkaline environment in anion-exchange membrane fuel cells allows the use of Pt-free electrocatalysts, thus reducing the system cost. We performed a theoretical high-throughput study of various low-cost Ag-based oxygen reduction reaction anode electrocatalysts and assessed their catalytic performance using density functional theory. From the Materials Project database, a total of 106 binary Ag alloys were investigated by estimating their heat of formation, dissolution potential, and overpotential on low-index surfaces. We confirmed that EuAg5, BaAg5, and SrAg5 have higher catalytic activities and durabilities than pure Ag. By following the chemical trend of the results, we further proposed LaAg5 and PrAg5, which were not included in the database, as promising candidates. All candidates are in the space group P6/mmm and contain alkaline earth metal or lanthanide elements.
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Affiliation(s)
- Jungwoo Choi
- Department of Materials Science and Engineering, Korea Advanced Instittue of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Soonho Kwon
- Department of Materials Science and Engineering, Korea Advanced Instittue of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Materials and Process Simulation Center (MSC), California Institute of Technology, Pasadena, California 91125, United States
| | - Youngtae Park
- Department of Materials Science and Engineering, Korea Advanced Instittue of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ku Kang
- Department of Materials Science and Engineering, Korea Advanced Instittue of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Chemical Biological and Radiological Defense Research Institute, Seoul, Republic of Korea
| | - Hyuck Mo Lee
- Department of Materials Science and Engineering, Korea Advanced Instittue of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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4
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Zhang N, Meng Y, Ning Y, Wheatley AEH, Chai F. A reusable catalyst based on CuO hexapods and a CuO-Ag composite for the highly efficient reduction of nitrophenols. RSC Adv 2021; 11:13193-13200. [PMID: 35423838 PMCID: PMC8697534 DOI: 10.1039/d1ra01560e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 03/30/2021] [Indexed: 11/26/2022] Open
Abstract
The enormous and urgent need to explore cost-effective catalysts with high efficiency has always been at the forefront of environmental protection and remediation research. This work develops a novel strategy for the fabrication of reusable CuO-based non-noble metal nanomaterials as high-efficiency catalysts. We report a facile and eco-friendly synthesis of CuO hexapods and CuO–Ag composite using uric acid as a reductant and protectant. Both exhibited high catalytic activity in the hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by sodium borohydride (NaBH4), with the CuO–Ag composite showing superior catalytic performance. Notably, the highest turnover frequency of CuO–Ag reached 7.97 × 10−2 s−1, which was much higher than numerous noble-metal nanomaterials. In addition, CuO hexapods and CuO–Ag composite were also shown to act as highly efficient and recyclable catalysts in the degeneration of 4-NP. Both CuO hexapods and the CuO–Ag composite exhibited outstanding catalytic durability, with no significant loss of activity over more than 10 cycles in the hydrogenation of 4-NP. Schematic illustration for the process of preparing CuO hexapods and CuO–Ag composite, and their application in catalytically reducing 4-NP and K3(Fe(CN)6).![]()
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Affiliation(s)
- Nannan Zhang
- Key Laboratory of Photochemical Biomaterials and Energy Storage Materials, Heilongjiang Province, Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, College of Chemistry and Chemical Engineering, Harbin Normal University Harbin 150025 Heilongjiang China
| | - Yuxi Meng
- Key Laboratory of Photochemical Biomaterials and Energy Storage Materials, Heilongjiang Province, Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, College of Chemistry and Chemical Engineering, Harbin Normal University Harbin 150025 Heilongjiang China
| | - Yuxue Ning
- Key Laboratory of Photochemical Biomaterials and Energy Storage Materials, Heilongjiang Province, Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, College of Chemistry and Chemical Engineering, Harbin Normal University Harbin 150025 Heilongjiang China
| | - Andrew E H Wheatley
- Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
| | - Fang Chai
- Key Laboratory of Photochemical Biomaterials and Energy Storage Materials, Heilongjiang Province, Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, College of Chemistry and Chemical Engineering, Harbin Normal University Harbin 150025 Heilongjiang China .,Department of Chemistry, University of Cambridge Lensfield Rd Cambridge CB2 1EW UK
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5
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Zhang N, Chen F, Jin Y, Wang J, Jin T, Kou B. Alloying effect in silver-based dilute nanoalloy catalysts for oxygen reduction reactions. J Catal 2020. [DOI: 10.1016/j.jcat.2020.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Lei H, Singh Siwal S, Zhang X, Zhang Q. Compositional and morphological engineering of in-situ-grown Ag nanoparticles on Cu substrate for enhancing oxygen reduction reaction activity: A novel electrochemical redox tuning approach. J Colloid Interface Sci 2020; 571:1-12. [PMID: 32182494 DOI: 10.1016/j.jcis.2020.03.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/06/2020] [Accepted: 03/07/2020] [Indexed: 10/24/2022]
Abstract
Silver nanoparticles (NPs) developed on a copper substrate, Ag NPs/Cu, are synthesized by a novel and facile galvanic replacement method performed in Ethaline deep eutectic solvent (DES). It reveals that the Ag NPs could be well dispersed on the Cu support via an in-situ electrochemical oxidation-reduction (ECO-ECR) activation process, which deliver significantly enhanced activity and stability for the oxygen reduction reaction (ORR) in alkaline media. The in-situ redox tuning triggers a reversible phase transformation of the formed initially Ag NPs, Ag ↔ Ag2O, with surface reconstruction and gives rise to a strong metal-support interaction with tailored atomic/electronic structures, resulting in enhanced ORR activity. Impressively, the introduction of NiII ions can regulate the galvanic replacement kinetics by mediating the diffusion of AgI ions and subsequent growth of Ag on the Cu surface in Ethaline, leading to the formation of uniformly distributed Ag NPs. Coupled with redox activation, the optimal Ag-Ni1 NPs/Cu_ECO-ECR exhibits ORR activity similar to that of the commercial state-of-the-art Pt/C catalyst, and better long-term durability (95% activity retention after 30,000 s), cyclic stability performance, and anti-poisoning capacity for methanol (96% after 3300 s), suggesting it a promising ORR electrocatalyst for practical application.
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Affiliation(s)
- Hao Lei
- Key Laboratory of Ionic Liquids Metallurgy, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China
| | - Samarjeet Singh Siwal
- Key Laboratory of Ionic Liquids Metallurgy, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China
| | - Xiaoying Zhang
- Kunming Metallurgy Research Institute, Kunming 650031, PR China
| | - Qibo Zhang
- Key Laboratory of Ionic Liquids Metallurgy, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization in Yunnan Province, Kunming 650093, PR China.
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7
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Zhang N, Chen F, Guo L. Catalytic activity of palladium-doped silver dilute nanoalloys for formate oxidation from a theoretical perspective. Phys Chem Chem Phys 2019; 21:22598-22610. [PMID: 31589222 DOI: 10.1039/c9cp04530a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The large-scale practical application of formate oxidation reaction (FOR) catalysts is hindered by their low activity and high cost. Herein, for the first time, a series of Pd-doped Ag dilute nanoalloys is demonstrated to have high catalytic activity in FOR with reduced consumption of Pd metals through density functional theory calculations, where the effects of potential, solvent and spin on catalytic performance are discussed. The Pd1Ag(111) single-atom alloy (SAA) exhibits higher FOR catalytic activity as reflected by the low limiting potential of 0.026 eV for the direct association path and a value of 0.084 eV for the direct dissociation path, and the lowest activation energy of 0.774 eV for the rate-determining-step in the direct dissociation path compared with Pd2Ag(111) and Pd3Ag(111) dilute alloys. Pd1Ag(111) SAA exhibits an extremely narrow sharp peak in the partial density of states from -0.75 to -2.0 eV, which is due to the free-atom-like electronic structure of the single Pd atom. The isolated Pd single atom is more stable by -0.041 and -0.097 eV, respectively, than the aggregated Pd2 and Pd3 atom clusters on the Ag(111) surface, which verifies the potential application of Pd1Ag(111) SAA in experiments. Overall, this work further elucidates the theoretical profile of FOR and provides a new strategy for designing the catalytic reaction at the atomic level.
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Affiliation(s)
- Nan Zhang
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, China.
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8
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Dong H, Liu C, Li Y, Jiang DE. Computational screening of M/Cu core/shell nanoparticles and their applications for the electro-chemical reduction of CO 2 and CO. NANOSCALE 2019; 11:11351-11359. [PMID: 31166347 DOI: 10.1039/c9nr01936g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To improve the catalytic activity of copper nanoparticles (Cu NPs) in the electro-chemical catalysis of the CO2 reduction reactions (CO2RRs), the formation and use of core/shell nanoparticles (CSNPs) with Cu as the shell composite may be an effective way. Using Cu79 NP as the representative, we performed computational screening and confirmed four Mx@Cu79-x CSNPs that can stably exist. Then, the catalytic performance of the screened CSNPs was tested through first-principles calculations. The free energy profiles indicate that Fe19@Cu60 is more desirable for CO2RR catalysis due to its high selectivity for CO rather than HCOOH at a low potential. Moreover, when it electro-catalyzes CO2 into CH4, the Fe19@Cu60 CSNP exhibits much lower limiting potential (-0.58 V) compared with pure Cu79 NP (-0.86 V) or the Cu (211) surface (-0.70 V). Taking the cost into consideration, the Fe19@Cu60 CSNP is highly recommended as a promising electro-catalyst for CO2RRs. In addition, when CO is taken as the initial reactant to be reduced, all the screened CSNPs exhibit lower limiting potentials than Cu79 NP. From the view of material design, the significant weakening of CO binding originating from the change in the d-band center could be the reason why the formation of a core/shell structure will enhance the catalytic performance of Cu NPs in CO reduction.
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Affiliation(s)
- Huilong Dong
- School of Chemistry and Materials Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
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9
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Takagi N, Nakagaki M, Ishimura K, Fukuda R, Ehara M, Sakaki S. Electronic processes in NO dimerization on Ag and Cu clusters: DFT and MRMP2 studies. J Comput Chem 2019; 40:181-190. [PMID: 30378149 DOI: 10.1002/jcc.25568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 11/10/2022]
Abstract
Experimentally observed NO dimerization on Cu and Ag surfaces is surprising because binding energy of NO dimer is very small in gas phase. MRMP2, MP2 to MP4, CCSD(T), and DFT studies of NO dimerization on Ag2 and Cu2 clusters disclosed that the CCSD(T) method could be applied to this reaction on Ag2 and Cu2 unlike NO dimerization in gas phase which exhibits significantly large nondynamical electron correlation effect. Charge-transfer (CT) from Ag2 and Cu2 to NO moieties plays important role in NN bond formation between two NO molecules. This CT considerably decreases nondynamical correlation effect. Also, the DFT method could be applied to this NO dimerization, if appropriate DFT functional is used; all pure functionals examined here and most of the hybrid functionals underestimated the activation barrier (Ea ), while only ωB97X provided Ea similar to CCSD(T)-calculated value. NO dimerization on similar Cu2 and Cu5 needs moderately larger Ea than those on Ag2 and Ag5 , because frontier orbital participating in the CT exists at lower energy in Cu2 and Cu5 than in Ag2 and Ag5 . The Ea decreases in the order Ag2 >> Ag38 > Ag7 ∼ Ag5 and the reaction energy (ΔE) is positive (endothermic) in Ag2 but significantly negative in Ag38 , Ag7 , and Ag5 , indicating that various Ag clusters could be effective for NO dimerization except for Ag2 . The decreasing order of Ea and increasing order of exothermicity are attributed to increasing order of the frontier orbital energy of Ag2 < Ag38 < Ag7 ∼ Ag5 . © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Nozomi Takagi
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan
| | - Masayuki Nakagaki
- Fukui Institute for Fundamental Chemistry (FIFC), Kyoto University, 34-4 Takano-Nishihiraki-cho, Sakyo-ku, Kyoto, 606-8103, Japan
| | - Kazuya Ishimura
- Institute for Molecular Science (IMS), Okazaki, 444-8585, Japan
| | - Ryoichi Fukuda
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan
| | - Masahiro Ehara
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan.,Institute for Molecular Science (IMS), Okazaki, 444-8585, Japan
| | - Shigeyoshi Sakaki
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan.,Fukui Institute for Fundamental Chemistry (FIFC), Kyoto University, 34-4 Takano-Nishihiraki-cho, Sakyo-ku, Kyoto, 606-8103, Japan
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10
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Hajinazar S, Sandoval ED, Cullo AJ, Kolmogorov AN. Multitribe evolutionary search for stable Cu-Pd-Ag nanoparticles using neural network models. Phys Chem Chem Phys 2019; 21:8729-8742. [PMID: 30968090 DOI: 10.1039/c9cp00837c] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We present an approach based on two bio-inspired algorithms to accelerate the identification of nanoparticle ground states. We show that a symbiotic co-evolution of nanoclusters across a range of sizes improves the search efficiency considerably, while a neural network constructed with a recently introduced stratified training scheme delivers an accurate description of interactions in multielement systems. The method's performance has been examined in extensive searches for stable elemental (30-80 atoms), binary (50, 55, and 80 atoms), and ternary (50, 55, and 80 atoms) Cu-Pd-Ag clusters. The best candidate structures identified with the neural network model have consistently lower energy at the density functional theory level compared with those found with traditional interatomic potentials.
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Affiliation(s)
- Samad Hajinazar
- Department of Physics, Applied Physics and Astronomy, Binghamton University, State University of New York, PO Box 6000, Binghamton, New York 13902-6000, USA
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11
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Mokkath JH. Band Edge Optical Excitation of Pyridine-Adsorbed CuAg Nanoparticles. J Phys Chem A 2018; 122:6467-6472. [PMID: 30044628 DOI: 10.1021/acs.jpca.8b03058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Understanding the structure-property relationship of multielement nanoparticles is vital for developing novel nanodevices. In the present paper, via a combination of a basin hopping global sampling method, a symmetry-orbit shell optimization technique, and density functional theory reoptimizations, we determine the energetically most stable CuAg face-centered cubic nanoparticles. The calculated structures show a clear tendency toward CucoreAgshell chemical ordering by populating the more cohesive Cu in the core region and of Ag in the shell region. Further, using time-dependent density functional theory (TDDFT) calculations, we analyze the band edge optical excitations of the nanoparticles with pyridine molecule on top. With the help of charge difference density plots, we found dramatic modifications in the electron density distribution of the nanoparticles. We believe that the present theoretical findings will be useful for the development of novel nanosensors.
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Affiliation(s)
- Junais Habeeb Mokkath
- Department of Physics , Kuwait College of Science and Technology , Doha Area, Seventh Ring Road , P.O. Box 27235, Kuwait
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12
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Sinthika S, Waghmare UV, Thapa R. Structural and Electronic Descriptors of Catalytic Activity of Graphene-Based Materials: First-Principles Theoretical Analysis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:1703609. [PMID: 29282859 DOI: 10.1002/smll.201703609] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 11/11/2017] [Indexed: 06/07/2023]
Abstract
Characteristic features of the d-band in electronic structure of transition metals are quite effective as descriptors of their catalytic activity toward oxygen reduction reaction (ORR). With the promise of graphene-based materials to replace precious metal catalysts, descriptors of their chemical activity are much needed. Here, a site-specific electronic descriptor is proposed based on the pz (π) orbital occupancy and its contribution to electronic states at the Fermi level. Simple structural descriptors are identified, and a linear predictive model is developed to precisely estimate adsorption free energies of OH (ΔGOH ) at various sites of doped graphene, and it is demonstrated through prediction of the most optimal site for catalysis of ORR. These structural descriptors, essentially the number of ortho, meta, and para sites of N/B-doped graphene sheet, can be extended to other doped sp2 hybridized systems, and greatly reduce the computational effort in estimating ΔGOH and site-specific catalytic activity.
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Affiliation(s)
- S Sinthika
- SRM Research Institute and Department of Physics and Nanotechnology, SRM University, Kattankulathur, 603203, Tamil Nadu, India
| | - Umesh V Waghmare
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, Karnataka, India
| | - Ranjit Thapa
- SRM Research Institute and Department of Physics and Nanotechnology, SRM University, Kattankulathur, 603203, Tamil Nadu, India
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13
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Thanh TD, Chuong ND, Hien HV, Kim NH, Lee JH. CuAg@Ag Core-Shell Nanostructure Encapsulated by N-Doped Graphene as a High-Performance Catalyst for Oxygen Reduction Reaction. ACS APPLIED MATERIALS & INTERFACES 2018; 10:4672-4681. [PMID: 29336546 DOI: 10.1021/acsami.7b16294] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Development of a robust, cost-effective, and efficient catalyst is extremely necessary for oxygen reduction reaction (ORR) in fuel cell applications. Herein, we reported a well-defined nanostructured catalyst of highly dispersed CuAg@Ag core-shell nanoparticle (NP)-encapsulated nitrogen-doped graphene nanosheets (CuAg@Ag/N-GNS) exhibiting a superior catalytic activity toward ORR in alkaline medium. The synergistic effects produced from the unique properties of CuAg@Ag core-shell NPs and N-GNS made such a novel nanohybrid display a catalytic behavior comparable to that of the commercial Pt/C product. In particular, it demonstrated a much better stability and methanol tolerance than Pt/C under the same conditions. Because of its outstanding electrochemical performance and ease of synthesis, CuAg@Ag/N-GNS material was expected to be a promising low-cost catalyst for ORR in alkaline fuel cell applications.
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Affiliation(s)
- Tran Duy Thanh
- Advanced Materials Institute of BIN Convergence Technology (BK21 Plus Global), Department of BIN Convergence Technology, and ‡Carbon Composite Research Centre, Department of Polymer & Nanoscience and Technology, Chonbuk National University , Jeonju, Jeonbuk 54896, Republic of Korea
| | - Nguyen Dinh Chuong
- Advanced Materials Institute of BIN Convergence Technology (BK21 Plus Global), Department of BIN Convergence Technology, and ‡Carbon Composite Research Centre, Department of Polymer & Nanoscience and Technology, Chonbuk National University , Jeonju, Jeonbuk 54896, Republic of Korea
| | - Hoa Van Hien
- Advanced Materials Institute of BIN Convergence Technology (BK21 Plus Global), Department of BIN Convergence Technology, and ‡Carbon Composite Research Centre, Department of Polymer & Nanoscience and Technology, Chonbuk National University , Jeonju, Jeonbuk 54896, Republic of Korea
| | - Nam Hoon Kim
- Advanced Materials Institute of BIN Convergence Technology (BK21 Plus Global), Department of BIN Convergence Technology, and ‡Carbon Composite Research Centre, Department of Polymer & Nanoscience and Technology, Chonbuk National University , Jeonju, Jeonbuk 54896, Republic of Korea
| | - Joong Hee Lee
- Advanced Materials Institute of BIN Convergence Technology (BK21 Plus Global), Department of BIN Convergence Technology, and ‡Carbon Composite Research Centre, Department of Polymer & Nanoscience and Technology, Chonbuk National University , Jeonju, Jeonbuk 54896, Republic of Korea
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14
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Effect of systematic addition of the third component on the melting characteristics and structural evolution of binary alloy nanoclusters. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.11.075] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Xiong R, Die D, Xiao L, Xu YG, Shen XY. Probing the Structural, Electronic, and Magnetic Properties of Ag n V (n = 1-12) Clusters. NANOSCALE RESEARCH LETTERS 2017; 12:625. [PMID: 29247393 PMCID: PMC5732125 DOI: 10.1186/s11671-017-2394-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 11/30/2017] [Indexed: 05/12/2023]
Abstract
The structural, electronic, and magnetic properties of Ag n V (n = 1-12) clusters have been studied using density functional theory and CALYPSO structure searching method. Geometry optimizations manifest that a vanadium atom in low-energy AgnV clusters favors the most highly coordinated location. The substitution of one V atom for an Ag atom in Ag n + 1 (n ≥ 5) cluster modifies the lowest energy structure of the host cluster. The infrared spectra, Raman spectra, and photoelectron spectra of Ag n V (n = 1-12) clusters are simulated and can be used to determine the most stable structure in the future. The relative stability, dissociation channel, and chemical activity of the ground states are analyzed through atomic averaged binding energy, dissociation energy, and energy gap. It is found that V atom can improve the stability of the host cluster, Ag2 excepted. The most possible dissociation channels are Ag n V = Ag + Ag n - 1V for n = 1 and 4-12 and Ag n V = Ag2 + Ag n - 2V for n = 2 and 3. The energy gap of Ag n V cluster with odd n is much smaller than that of Ag n + 1 cluster. Analyses of magnetic property indicate that the total magnetic moment of Ag n V cluster mostly comes from V atom and varies from 1 to 5 μ B. The charge transfer between V and Ag atoms should be responsible for the change of magnetic moment.
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Affiliation(s)
- Ran Xiong
- School of Science, Xihua University, Chengdu, 610039 China
| | - Dong Die
- School of Science, Xihua University, Chengdu, 610039 China
| | - Lu Xiao
- School of Science, Xihua University, Chengdu, 610039 China
| | - Yong-Gen Xu
- School of Science, Xihua University, Chengdu, 610039 China
| | - Xu-Ying Shen
- School of Science, Xihua University, Chengdu, 610039 China
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16
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Hong Q, Lu H. In-situ Electrodeposition of Highly Active Silver Catalyst on Carbon Fiber Papers as Binder Free Cathodes for Aluminum-air Battery. Sci Rep 2017; 7:3378. [PMID: 28611456 PMCID: PMC5469864 DOI: 10.1038/s41598-017-03609-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/11/2017] [Indexed: 12/16/2022] Open
Abstract
Carbon fiber papers supported Ag catalysts (Ag/CFP) with different coverage of electro-active site are prepared by electrochemical deposition and used as binder free cathodes in primary aluminum-air (Al-air) battery. Scanning Electron Microscopy and X-ray Diffraction studies are carried out to characterize the as-prepared Ag/CFP air cathodes. Oxygen reduction reaction (ORR) activities on these air cathodes in alkaline solutions are systematic studied. A newly designed aluminum-air cell is used to further determine the cathodes performance under real operation condition and during the test, the Ag/CFP electrodes show outstanding catalytic activity for ORR in concentrated alkaline electrolyte, and no obvious activity degradation is observed after long-time discharge. The electrochemical test results display the dependence of coverage of the electro-active Ag on the catalytic performance of the air cathodes. The resulting primary Al-air battery made from the best-performing cathode shows an impressive discharge peak power density, outperforming that of using commercial nano-manganese catalyst air electrodes.
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Affiliation(s)
- Qingshui Hong
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Huimin Lu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
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17
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Wu X, Chen F, Zhang N, Qaseem A, Johnston RL. Engineering Bimetallic Ag-Cu Nanoalloys for Highly Efficient Oxygen Reduction Catalysts: A Guideline for Designing Ag-Based Electrocatalysts with Activity Comparable to Pt/C-20. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1603876. [PMID: 28296197 DOI: 10.1002/smll.201603876] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/03/2017] [Indexed: 06/06/2023]
Abstract
Development of highly active and stable Pt-free oxygen reduction reaction catalysts from earth-abundant elements remains a grand challenge for highly demanded metal-air batteries. Ag-based alloys have many advantages over platinum group catalysts due to their low cost, high stability, and acceptable oxygen reduction reaction (ORR) performance in alkaline solutions. Nevertheless, compared to commercial Pt/C-20%, their catalytic activity still cannot meet the demand of commercialization. In this study, a kind of catalysts screening strategy on Agx Cu100-x nanoalloys is reported, containing the surface modification method, studies of activity enhancement mechanism, and applied research on zinc-air batteries. The results exhibit that the role of selective dealloying (DE) or galvanic displacement (GD) is limited by the "parting limitation", and this "parting limitation" determines the surface topography, position of d-band center, and ORR performance of Agx Cu100-x alloys. The GD-Ag55 Cu45 and DE-Ag25 Cu75 catalysts alloys present excellent ORR performance that is comparable to Pt/C-20%. The relationship between electronic perturbation and specific activity demonstrates that positive shift of the d-band center (≈0.12 eV, relative to Ag) for GD-Ag55 Cu45 is beneficial for ORR, which is contrary to Pt-based alloys (negative shift, ≈0.1 eV). Meanwhile, extensive electrochemical and electronic structure characterization indicates that the high work function of GD-Ag55 Cu45 (4.8 eV) is the reason behind their excellent durability for zinc-air batteries.
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Affiliation(s)
- Xiaoqiang Wu
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Fuyi Chen
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Nan Zhang
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Adnan Qaseem
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Roy L Johnston
- School of Chemistry, University of Birmingham, Birmingham, B15 2TT, UK
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18
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Wu X, Chen F, Zhang N, Lei Y, Jin Y, Qaseem A, Johnston RL. Activity Trends of Binary Silver Alloy Nanocatalysts for Oxygen Reduction Reaction in Alkaline Media. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1603387. [PMID: 28151572 DOI: 10.1002/smll.201603387] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/08/2016] [Indexed: 06/06/2023]
Abstract
The electrocatalytic activity of Pt-based alloys exhibits a strong dependence on their electronic structures, but a relationship between electronic structure and oxygen reduction reaction (ORR) activity in Ag-based alloys is still not clear. Here, a vapor deposition based approach is reported for the preparation of Ag75 M25 (M = Cu, Co, Fe, and In) and Agx Cu100-x (x = 0, 25, 45, 50, 55, 75, 90, and 100) nanocatalysts and their electronic structures are determined by valence band spectra. The relationship of the d-band center and ORR activity exhibits volcano-shape behaviors, where the maximum catalytic activity is obtained for Ag75 Cu25 alloys. The ORR enhancement of Ag75 Cu25 alloys originates from the 0.12 eV upshift in d-band center relative to pure Ag, which is different from the downshift in the d-band center in Pt-based alloys. The activity trend for these Ag75 M25 alloys is in the order of Ag75 Cu25 > Ag75 Fe25 > Ag75 Co25 . These results provide an insight to understand the activity and stability enhancement of Ag75 Cu25 and Ag50 Cu50 catalysts by alloying.
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Affiliation(s)
- Xiaoqiang Wu
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Fuyi Chen
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Nan Zhang
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Yimin Lei
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Yachao Jin
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Adnan Qaseem
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian, 710072, China
| | - Roy L Johnston
- School of Chemistry, University of Birmingham, Birmingham, B15 2TT, UK
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19
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Kumar S. Effect of applied force and atomic organization of copper on its adhesion to a graphene substrate. RSC Adv 2017. [DOI: 10.1039/c7ra01873h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Copper/graphene composites are lightweight and possess many attractive properties such as improved mechanical, electrical, and thermal properties.
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Affiliation(s)
- Sunil Kumar
- Metal Extraction and Forming Division
- CSIR
- -National Metallurgical Laboratory
- Jamshedpur
- 831007 India
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20
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Qaseem A, Chen F, Wu X, Johnston RL. Pt-free silver nanoalloy electrocatalysts for oxygen reduction reaction in alkaline media. Catal Sci Technol 2016. [DOI: 10.1039/c5cy02270c] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Silver nanoalloy electrocatalysts with comparable activity and better stability than commercial Pt/C for oxygen reduction reaction (ORR) in advanced metal–air batteries and fuel cells.
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Affiliation(s)
- Adnan Qaseem
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xian
- China
| | - Fuyi Chen
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xian
- China
| | - Xiaoqiang Wu
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xian
- China
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