| 1. |
- Fan, Lizhou, et al.
(author)
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Molecular Functionalization of NiO Nanocatalyst for Enhanced Water Oxidation by Electronic Structure Engineering
- 2020
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In: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 13:22, s. 5901-5909
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Journal article (peer-reviewed)abstract
- Tuning the local environment of nanomaterial-based catalysts has emerged as an effective approach to optimize their oxygen evolution reaction (OER) performance, yet the controlled electronic modulation around surface active sites remains a great challenge. Herein, directed electronic modulation of NiO nanoparticles was achieved by simple surface molecular modification with small organic molecules. By adjusting the electronic properties of modifying molecules, the local electronic structure was rationally tailored and a close electronic structure-activity relationship was discovered: the increasing electron-withdrawing modification readily decreased the electron density around surface Ni sites, accelerating the reaction kinetics and improving OER activity, and vice versa. Detailed investigation by operando Raman spectroelectrochemistry revealed that the electron-withdrawing modification facilitates the charge-transfer kinetics, stimulates the catalyst reconstruction, and promotes abundant high-valent gamma-NiOOH reactive species generation. The NiO-C(6)F(5)catalyst, with the optimized electronic environment, exhibited superior performance towards water oxidation. This work provides a well-designed and effective approach for heterogeneous catalyst fabrication under the molecular level.
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| 2. |
- Guo, Yaxiao, et al.
(author)
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Molybdenum and boron synergistically boosting efficient electrochemical nitrogen fixation
- 2020
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In: Nano Energy. - : Elsevier Ltd. - 2211-2855 .- 2211-3282. ; 78
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Journal article (peer-reviewed)abstract
- Ammonia production consumes ~2% of the annual worldwide energy supply, therefore strategic alternatives for the energy-intensive ammonia synthesis through the Haber-Bosch process are of great importance to reduce our carbon footprint. Inspired by MoFe-nitrogenase and the energy-efficient and industrially feasible electrocatalytic synthesis of ammonia, we herein establish a catalytic electrode for artificial nitrogen fixation, featuring a carbon fiber cloth fully grafted by boron-doped molybdenum disulfide (B-MoS2/CFC) nanosheets. An excellent ammonia production rate of 44.09 μg h–1 cm–2 is obtained at −0.2 V versus the reversible hydrogen electrode (RHE), whilst maintaining one of the best reported Faradaic efficiency (FE) of 21.72% in acidic aqueous electrolyte (0.1 M HCl). Further applying a more negative potential of −0.25 V renders the best ammonia production rate of 50.51 μg h–1 cm–2. A strong-weak electron polarization (SWEP) pair from the different electron accepting and back-donating capacities of boron and molybdenum (2p shell for boron and 5d shell for molybdenum) is proposed to facilitate greatly the adsorption of non-polar dinitrogen gas via N≡N bond polarization and the first protonation with large driving force. In addition, for the first time a visible light driven photo-electrochemical (PEC) cell for overall production of ammonia, hydrogen and oxygen from water + nitrogen, is demonstrated by coupling a bismuth vanadate BiVO4 photo-anode with the B-MoS2/CFC catalytic cathode.
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| 3. |
- Zhang, Biaobiao, et al.
(author)
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Advancing Proton Exchange Membrane Electrolyzers with Molecular Catalysts
- 2020
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In: Joule. - : Elsevier BV. - 2542-4351. ; 4:7, s. 1408-1444
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Research review (peer-reviewed)abstract
- Molecular catalysts possess numerous advantages over conventional heterogeneous catalysts in precise structure regulation, in-depth mechanism understanding, and efficient metal utilization. Various molecular catalysts have been reported that efficiently catalyze reactions involved in artificial photosynthesis, however, these catalysts have been rarely considered in view of practical applications. With this review, firstly we demonstrate in the introduction that molecular catalysts can bring new opportunities to proton exchange membrane (PEM) electrolyzers. In the following parts, we provide an overview of molecular catalyst modified carbon materials developed for electrochemical water oxidation, proton reduction, and CO2 reduction reactions. These materials and the involved immobilization strategies as well as characterization techniques may be directly employed in the investigations of application of molecular catalysts in PEM electrolyzers. The future scientific perspectives and challenges to advance this promising, yet underdeveloped technology for solar fuel production, integrating PEM electrolyzer with molecular-level catalysis, are discussed in the conclusions.
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