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van Zyl WE, Liu CW. Interstitial hydrides in nanoclusters can reduce M(I) (M = Cu, Ag, Au) to M(0) and form stable superatoms. Chemistry 2021; 28:e202104241. [PMID: 34936722 DOI: 10.1002/chem.202104241] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Indexed: 11/11/2022]
Abstract
High-nuclearity clusters resemble the closest model between the determination of atomically precise chemical species and the bulk metallic version thereof, and both impacts on a variety of applications, including catalysis, optics, sensors, and new energy sources. Our interest lies with the nanoclusters of the Group 11 (Cu, Ag, Au) metals stabilized by dichalcogenido and hydrido ligands. Herein, we describe superatoms formed by the clusters and their relationship with precursor hydrido clusters. Specifically, our concept seeks to demonstrate a possible correlation that exist between hydrido clusters (and nanoalloys) and the formation of superatoms, with the loss of hydrides and typically with release of H 2 gas. These reactions appear to be internal self-redox reactions and require no additional reducing agent, but does seem to require a similar core structure. Knowledge of such processes could provide insight into how clusters grow and an understanding in bridging the atomically precise cluster - metal nanoparticle mechanism.
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Affiliation(s)
- Werner E van Zyl
- University of Kwazulu-Natal, School of Chemistry and Physics, SOUTH AFRICA
| | - Chen-Wei Liu
- National Dong Hwa University, Department of Chemistry, 1, section 2, University drive, 974, Hualien, TAIWAN
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Chen Z, Miao L, Fu Y, Shi L, Chen J, Liu X, Zhang L. Engineering Functional Interface with Built-in Catalytic and Self-Oxidation Sites for Highly Stable Lithium-Sulfur Batteries. Chemistry 2021; 27:14444-14450. [PMID: 34347317 DOI: 10.1002/chem.202101625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Indexed: 11/11/2022]
Abstract
Lithium-sulfur (Li-S) batteries have attracted great attention due to their high theoretical energy density. The rapid redox conversion of lithium polysulfides (LiPS) is effective for solving the serious shuttle effect and improving the utilization of active materials. The functional design of the separator interface with fast charge transfer and active catalytic sites is desirable for accelerating the conversion of intermediates. Herein, a graphene-wrapped MnCO3 nanowire (G@MC) was prepared and utilized to engineer the separator interface. G@MC with active Mn2+ sites can effectively anchor the LiPS by forming the Mn-S chemical bond according to our theoretical calculation results. In addition, the catalytic Mn2+ sites and conductive graphene layer of G@MC could accelerate the reversible conversion of LiPS via the spontaneous "self-redox" reaction and the rapid electron transfer in electrochemical process. As a result, the G@MC-based battery exhibits only 0.038 % capacity decay (per cycle) after 1000 cycles at 2.0 C. This work affords new insights for designing the integrated functional interface for stable Li-S batteries.
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Affiliation(s)
- Zihan Chen
- The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Licheng Miao
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yancheng Fu
- The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Leyuan Shi
- The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Jinzhou Chen
- The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Xuying Liu
- The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Linlin Zhang
- The Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.,Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071, P. R. China
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Zhang T, Shang H, Zhang B, Yan D, Xiang X. Ag/Ultrathin-Layered Double Hydroxide Nanosheets Induced by a Self-Redox Strategy for Highly Selective CO 2 Reduction. ACS Appl Mater Interfaces 2021; 13:16536-16544. [PMID: 33793186 DOI: 10.1021/acsami.1c02737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The carbon-neutral photocatalytic CO2 reduction reaction (CO2RR) enables the conversion of CO2 into hydrocarbon fuels or value-added chemicals under mild conditions. Achieving high selectivity for the desired products of the CO2RR remains challenging. Herein, a self-redox strategy is developed to construct strong interfacial bonds between Ag nanoparticles and an ultrathin CoAl-layered double hydroxide (U-LDH) nanosheet support, where the surface hydroxyl groups associated with oxygen vacancies of U-LDH play a critical role in the formation of the interface structure. The supported Ag@U-LDH acts as a highly efficient catalyst for CO2 reduction, resulting in a high CO evolution rate of 757 μmol gcat-1 h-1 and a CO selectivity of 94.5% under light irradiation. Such a high catalytic selectivity may represent a new record among current photocatalytic CO2RR to CO systems. The Ag-O-Co interface bonding is confirmed by Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and FTIR CO2 adsorption studies. The in situ FTIR measurements indicate that the formation of the *COOH intermediate is accelerated and the mass transfer is improved during the CO2RR. Density functional theory calculations show that the Ag-O-Co interface reduces the formation energy of the *COOH intermediate and accumulates localized charge. Experimental and theoretical analysis collectively demonstrates that the strong interface bonding between Ag and U-LDH activates the interface structure as catalytically CO2RR active sites, effectively optimizing the binding energies with reacted intermediates and facilitating the CO2RR performance.
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Affiliation(s)
- Tingting Zhang
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Huishan Shang
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Bing Zhang
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Dongpeng Yan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xu Xiang
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
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Abstract
The presence of extra reducer was thought to be essential for producing natural diamonds from reduction of carbonates. The present study of the Xiuyan meteoritic crater, however, finds natural diamond formation via a subsolidus self-redox of a ferromagnesian carbonate during shock compression to 25–45 GPa and 800–900 °C without melting, fluid, and another reductant. The ability of carbonate to produce diamond by itself implies that diamond would be a very common mineral in the lower mantle where the carbonates are abundant and pressures and temperatures are sufficiently high. Formation of natural diamonds requires the reduction of carbon to its bare elemental form, and pressures (P) greater than 5 GPa to cross the graphite–diamond transition boundary. In a study of shocked ferromagnesian carbonate at the Xiuyan impact crater, we found that the impact pressure–temperature (P-T) of 25–45 GPa and 800–900 °C were sufficient to decompose ankerite Ca(Fe2+,Mg)(CO3)2 to form diamond in the absence of another reductant. The carbonate self-reduced to diamond by concurrent oxidation of Fe2+ to Fe3+ to form a high-P polymorph of magnesioferrite, MgFe3+2O4. Discovery of the subsolidus carbonate self-reduction mechanism indicates that diamonds could be ubiquitously present as a dominant host for carbon in the Earth’s lower mantle.
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