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Journal ArticleDOI: 10.1021/JACS.1C01096

Co-Cu Bimetallic Metal Organic Framework Catalyst Outperforms the Pt/C Benchmark for Oxygen Reduction.

04 Mar 2021-Journal of the American Chemical Society (American Chemical Society)-Vol. 143, Iss: 10, pp 4064-4073
Abstract: Platinum (Pt)-based-nanomaterials are currently the most successful catalysts for the oxygen reduction reaction (ORR) in electrochemical energy conversion devices such as fuel cells and metal-air batteries. Nonetheless, Pt catalysts have serious drawbacks, including low abundance in nature, sluggish kinetics, and very high costs, which limit their practical applications. Herein, we report the first rationally designed nonprecious Co-Cu bimetallic metal-organic framework (MOF) using a low-temperature hydrothermal method that outperforms the electrocatalytic activity of Pt/C for ORR in alkaline environments. The MOF catalyst surpassed the ORR performance of Pt/C, exhibiting an onset potential of 1.06 V vs RHE, a half-wave potential of 0.95 V vs RHE, and a higher electrochemical stability (ΔE1/2 = 30 mV) after 1000 ORR cycles in 0.1 M NaOH. Additionally, it outperformed Pt/C in terms of power density and cyclability in zinc-air batteries. This outstanding behavior was attributed to the unique electronic synergy of the Co-Cu bimetallic centers in the MOF network, which was revealed by XPS and PDOS.

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20 results found

Journal ArticleDOI: 10.1016/J.IJHYDENE.2021.03.248
Abstract: The development of efficient photoelectrodes via defect engineering of wide-band gap metal oxides has been the prime focus for many years. Specifically, the effect of carbon defects in wide-band gap metal oxides on their performance in photoelectrochemical (PEC) applications raised numerous controversies and still elusive. Herein, the effect of various carbon defects in m-ZrO2 was investigated using the density functional theory to probe the thermodynamic, electronic, and optical properties of the defective structures against pristine m-ZrO2. The defect formation energies revealed that elevating the temperature promotes and facilitates the formation of carbon defects. Moreover, the binding energies confirmed the stability of all studied complex carbon defects. Furthermore, the band edge positions against the redox potentials of water species revealed that all the studied defective structures can serve as photoanodes for water splitting. Additionally, CO3c (carbon atom substituted O3c site) was the only defective structure that exhibited slight straddling of the redox potentials of water. Importantly, all investigated defective structures enhanced light absorption with different optical activities. It is worth mentioning that our results showed exceptional reduction in the bandgap energy compared to those reported experimentally for ZrO2-based materials. Finally, CO3cVO3c (carbon atom substituted O3c associated with O3c vacancy) defective m-ZrO2 enjoyed lowest sub-bandgap (1.9 eV), low defect formation energy, low exciton binding energy, high mobility of charge carriers, fast charge transfer, and low recombination rate. Concurrently, its optical properties were exceptional in terms of high absorption, low reflectivity and improved static dielectric constant. Hence, the study recommends CO3cVO3c defective m-ZrO2 as the leading candidate to serve as a photoanode for PEC applications.

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Topics: Vacancy defect (56%), Band gap (51%), Water splitting (51%)

3 Citations

Journal ArticleDOI: 10.1016/J.MCAT.2021.111710
Abstract: Despite being one of the most buoyant and trailblazing green energy generation technology, the effective applications of direct methanol fuel cell is challenging mostly due to unavailability of suitably efficient, durable and cost effective catalyst for methanol oxidation reaction. The key features those should be rendered in the electrocatalytic materials are: good electrical conductivity, high surface area, mesoporous structure, excellent chemical stability towards acidic and alkaline medium, and acceptable resistivity toward corrosion. In recent years, one such emerging area of electrocatalysts are metal organic frameworks and the corresponding derived composite materials. The object of this review is to provide an impression of recent progresses in the area of metal organic frameworks and their derivatives for methanol oxidation reaction. The review compiles the synthesis strategies of those framework materials and their derivatives that are extensively being used in methanol oxidation reaction. The electrocatalytic reactivity in correlation with the structure and surface properties of the framework materials are addressed in detail.

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2 Citations

Journal ArticleDOI: 10.1016/J.APCATB.2021.120415
Man Guo1, Meijiao Xu1, Yuan Qu1, Chuan Hu1  +3 moreInstitutions (2)
Abstract: Developing high-efficient non-noble metal-based catalysts for oxygen reduction reaction (ORR) is an inevitable way to improve Zinc-air batteries' performance (ZAB). Herein, we report a Cu3P/MoP electrocatalyst (Cu3P/MoP@C) supported by hollow-porous-carbon nanospheres displaying high electrocatalytic activity and exceptional durability in alkaline media. The optimized ORR catalyst outperformed the benchmark Pt/C (20 wt%) and most recently reported Cu-/Mo-based catalysts in various aspects. X-ray photoelectron spectroscopy reveals that the excellent ORR performance originates from the charge transfer between of Cu3P and MoP species. Besides, the large specific surface area of Cu3P/MoP@C with mesoporous structure is particularly advantageous for the inner surface contact with electrolyte to accelerate ORR kinetics. Moreover, Cu3P/MoP@C also exhibits a large power density of 156 mW cm−2, a high round-trip efficiency, and superb stability over 231 h superior to Pt/C in the ZAB. This work offers a scalable and promising approach for the rational fabrication of hollow porous structure materials.

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Topics: Electrocatalyst (53%)

1 Citations

Journal ArticleDOI: 10.1021/ACSENERGYLETT.1C01302
Yunhe Zhao1, Yunhe Zhao2, Yizhan Wang1, Yutao Dong1  +9 moreInstitutions (2)
30 Aug 2021-ACS energy letters
Abstract: The extremely large surface area offered by quasi-two-dimensional (2D) nanostructures is a great advantage for catalytic applications. While bimetallic materials have been discovered as a group of ...

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Topics: Bimetallic strip (52%), Oxygen evolution (50%)

1 Citations


48 results found

Journal ArticleDOI: 10.1063/1.1316015
Abstract: Recent extensions of the DMol3 local orbital density functional method for band structure calculations of insulating and metallic solids are described. Furthermore the method for calculating semilocal pseudopotential matrix elements and basis functions are detailed together with other unpublished parts of the methodology pertaining to gradient functionals and local orbital basis sets. The method is applied to calculations of the enthalpy of formation of a set of molecules and solids. We find that the present numerical localized basis sets yield improved results as compared to previous results for the same functionals. Enthalpies for the formation of H, N, O, F, Cl, and C, Si, S atoms from the thermodynamic reference states are calculated at the same level of theory. It is found that the performance in predicting molecular enthalpies of formation is markedly improved for the Perdew–Burke–Ernzerhof [Phys. Rev. Lett. 77, 3865 (1996)] functional.

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Topics: Density functional theory (57%), DMol3 (55%), Pseudopotential (53%) ... show more

7,255 Citations

Journal ArticleDOI: 10.1021/AR000034B
Mohamed Eddaoudi1, David B. Moler2, Hailian Li2, Banglin Chen2  +3 moreInstitutions (2)
Abstract: Secondary building units (SBUs) are molecular complexes and cluster entities in which ligand coordination modes and metal coordination environments can be utilized in the transformation of these fragments into extended porous networks using polytopic linkers (1,4-benzenedicarboxylate, 1,3,5,7-adamantanetetracarboxylate, etc.). Consideration of the geometric and chemical attributes of the SBUs and linkers leads to prediction of the framework topology, and in turn to the design and synthesis of a new class of porous materials with robust structures and high porosity.

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Topics: SBus (58%)

4,604 Citations

Open accessJournal ArticleDOI: 10.1038/NMAT3087
Yongye Liang1, Yanguang Li1, Hailiang Wang1, Jigang Zhou2  +3 moreInstitutions (2)
01 Oct 2011-Nature Materials
Abstract: Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable-energy technologies including fuel cells and water splitting. Despite tremendous efforts, developing oxygen electrode catalysts with high activity at low cost remains a great challenge. Here, we report a hybrid material consisting of Co₃O₄ nanocrystals grown on reduced graphene oxide as a high-performance bi-functional catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Although Co₃O₄ or graphene oxide alone has little catalytic activity, their hybrid exhibits an unexpected, surprisingly high ORR activity that is further enhanced by nitrogen doping of graphene. The Co₃O₄/N-doped graphene hybrid exhibits similar catalytic activity but superior stability to Pt in alkaline solutions. The same hybrid is also highly active for OER, making it a high-performance non-precious metal-based bi-catalyst for both ORR and OER. The unusual catalytic activity arises from synergetic chemical coupling effects between Co₃O₄ and graphene.

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Topics: Graphene (55%), Oxygen evolution (55%), Water splitting (53%) ... show more

4,454 Citations

Journal ArticleDOI: 10.1126/SCIENCE.1212858
09 Dec 2011-Science
Abstract: The efficiency of many energy storage technologies, such as rechargeable metal-air batteries and hydrogen production from water splitting, is limited by the slow kinetics of the oxygen evolution reaction (OER). We found that Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3–δ (BSCF) catalyzes the OER with intrinsic activity that is at least an order of magnitude higher than that of the state-of-the-art iridium oxide catalyst in alkaline media. The high activity of BSCF was predicted from a design principle established by systematic examination of more than 10 transition metal oxides, which showed that the intrinsic OER activity exhibits a volcano-shaped dependence on the occupancy of the 3d electron with an e g symmetry of surface transition metal cations in an oxide. The peak OER activity was predicted to be at an e g occupancy close to unity, with high covalency of transition metal–oxygen bonds.

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Topics: Oxide (54%), Oxygen evolution (53%), Perovskite (structure) (52%) ... show more

3,135 Citations

Open accessJournal ArticleDOI: 10.1039/B817735J
Abstract: This critical review presents a comprehensive study of transition-metal carboxylate clusters which may serve as secondary building units (SBUs) towards construction and synthesis of metal–organic frameworks (MOFs). We describe the geometries of 131 SBUs, their connectivity and composition. This contribution presents a comprehensive list of the wide variety of transition-metal carboxylate clusters which may serve as secondary building units (SBUs) in the construction and synthesis of metal–organic frameworks. The SBUs discussed here were obtained from a search of molecules and extended structures archived in the Cambridge Structure Database (CSD, version 5.28, January 2007) which included only crystals containing metal carboxylate linkages (241 references).

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Topics: SBus (62%)

1,974 Citations