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Qin S, Duan Y, Zhang XL, Zheng LR, Gao FY, Yang PP, Niu ZZ, Liu R, Yang Y, Zheng XS, Zhu JF, Gao MR. Ternary nickel-tungsten-copper alloy rivals platinum for catalyzing alkaline hydrogen oxidation. Nat Commun 2021; 12:2686. [PMID: 33976204 PMCID: PMC8113563 DOI: 10.1038/s41467-021-22996-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/09/2021] [Indexed: 11/09/2022] Open
Abstract
Operating fuel cells in alkaline environments permits the use of platinum-group-metal-free (PGM-free) catalysts and inexpensive bipolar plates, leading to significant cost reduction. Of the PGM-free catalysts explored, however, only a few nickel-based materials are active for catalyzing the hydrogen oxidation reaction (HOR) in alkali; moreover, these catalysts deactivate rapidly at high anode potentials owing to nickel hydroxide formation. Here we describe that a nickel-tungsten-copper (Ni5.2WCu2.2) ternary alloy showing HOR activity rivals Pt/C benchmark in alkaline electrolyte. Importantly, we achieved a high anode potential up to 0.3 V versus reversible hydrogen electrode on this catalyst with good operational stability over 20 h. The catalyst also displays excellent CO-tolerant ability that Pt/C catalyst lacks. Experimental and theoretical studies uncover that nickel, tungsten, and copper play in synergy to create a favorable alloying surface for optimized hydrogen and hydroxyl bindings, as well as for the improved oxidation resistance, which result in the HOR enhancement.
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Affiliation(s)
- Shuai Qin
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Yu Duan
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Xiao-Long Zhang
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Li-Rong Zheng
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Fei-Yue Gao
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Peng-Peng Yang
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Zhuang-Zhuang Niu
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Ren Liu
- Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, China
| | - Yu Yang
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Xu-Sheng Zheng
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China
| | - Jun-Fa Zhu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China
| | - Min-Rui Gao
- Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.
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Abstract
Calculations on the Cu24(m-BDC)24 (m-BDC = 1,3-benzenedicarboxylate) polyoxometalate (POM) cage with 0, 12, 24, and 40 methane molecules inside were made using the M06 exchange/correlation functional. During filling of the cage with 40 CH4 molecules, the 12 strongest binding CH4 molecules are those to the coordination unsaturated sites (CUS) to the inwardly directed Cu(+2) centers via agostic interactions. The next 12 CH4 molecules are less tightly bound followed by the next 16 CH4 molecules with average binding energies of 8.27, 7.88, and 7.36 kcal/mol per CH4, respectively. A section of the Cu24(m-BDC)24 cage was taken with the formula Cu4(m-BDC)(BC)6 (BC = benezenecarboxylate) in order to estimate zero-point, thermal, and entropy corrections of the larger cage. Estimating free energies at 1 bar, the Cu24(m-BDC)24 POM is predicted to lose 16, 12, and 12 CH4 molecules at 67, 123, and 171 °C, respectively. The 40CH4@Cu24(m-BDC)24 cage, which is isostructural to the main cavity of HKUST-1 with 40 CH4 molecules inside, is predicted to have a loading of 224 cm3(STP) cm-3 at 1 bar.
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Affiliation(s)
- Michael L McKee
- Department of Chemistry and Biochemistry , Auburn University , Auburn , Alabama 36849 , United States
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Cockayne E. Density Functional Theory Meta GGA Study of Water Adsorption in MIL-53(Cr). POWDER DIFFRACTION 2019; 34:10.1017/s0885715619000587. [PMID: 32165784 PMCID: PMC7067281 DOI: 10.1017/s0885715619000587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We use density functional theory meta-GGA TPSS+D3(BJ)+U+J calculations to investigate the energetics and geometry of water molecules in the flexible metal-organic framework material MIL-53(Cr) as a function of cell volume. The critical concentration of water to cause the transition from the large pore (lp) to the narrow pore (np) structure is estimated to be about 0.13 water molecule per Cr. At a concentration x = 1 water molecule per Cr, the zero-temperature np and lp configurations each have a hydrogen bond between the H of each framework hydroxyl group and a water oxygen (O W ). At intermediate volumes, water dimer-like configurations are observed. A concentration x = 1.25 leads to hydrogen bonding between water molecules in the np phase that is absent for x = 1. Our results suggest possible mechanisms for pore closing in hydrated MIL-53(Cr).
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Affiliation(s)
- Eric Cockayne
- Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 USA
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Yu J, Xie LH, Li JR, Ma Y, Seminario JM, Balbuena PB. CO 2 Capture and Separations Using MOFs: Computational and Experimental Studies. Chem Rev 2017; 117:9674-9754. [PMID: 28394578 DOI: 10.1021/acs.chemrev.6b00626] [Citation(s) in RCA: 485] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This Review focuses on research oriented toward elucidation of the various aspects that determine adsorption of CO2 in metal-organic frameworks and its separation from gas mixtures found in industrial processes. It includes theoretical, experimental, and combined approaches able to characterize the materials, investigate the adsorption/desorption/reaction properties of the adsorbates inside such environments, screen and design new materials, and analyze additional factors such as material regenerability, stability, effects of impurities, and cost among several factors that influence the effectiveness of the separations. CO2 adsorption, separations, and membranes are reviewed followed by an analysis of the effects of stability, impurities, and process operation conditions on practical applications.
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Affiliation(s)
| | | | | | - Yuguang Ma
- Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States
| | - Jorge M Seminario
- Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States
| | - Perla B Balbuena
- Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States
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Cockayne E. Thermodynamics of the Flexible Metal-Organic Framework Material MIL-53(Cr) From First Principles. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:4312-4317. [PMID: 28690713 PMCID: PMC5497523 DOI: 10.1021/acs.jpcc.6b11692] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We use first-principles density functional theory total energy and linear response phonon calculations to compute the Helmholtz and Gibbs free energy as a function of temperature, pressure, and cell volume in the flexible metal-organic framework material MIL-53(Cr) within the quasiharmonic approximation. GGA and metaGGA calculations were performed, each including empirical van der Waals (vdW) forces under the D2, D3, or D3(BJ) parameterizations. At all temperatures up to 500 K and pressures from -30 MPa to 30 MPa, two minima in the free energy versus volume are found, corresponding to the narrow pore (np) and large pore (lp) structures. Critical positive and negative pressures are identified, beyond which there is only one free energy minimum. While all results overestimated the stability of the np phase relative to the lp phase, the best overall agreement with experiment is found for the metaGGA PBEsol+RTPSS+U+J approach with D3 or D3(BJ) vdW forces. For these parameterizations, the calculated free energy barrier for the np-lp transition is only 3 to 6 kJ per mole of Cr4(OH)4(C8H4O4)4.
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Affiliation(s)
- Eric Cockayne
- Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 USA
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