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Nie Y, Sun Y, Song B, Meyer Q, Liu S, Guo H, Tao L, Lin F, Luo M, Zhang Q, Gu L, Yang L, Zhao C, Guo S. Low-Electronegativity Mn-Contraction of PtMn Nanodendrites Boosts Oxygen Reduction Durability. Angew Chem Int Ed Engl 2024; 63:e202317987. [PMID: 38152839 DOI: 10.1002/anie.202317987] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/25/2023] [Accepted: 12/27/2023] [Indexed: 12/29/2023]
Abstract
Platinum metal (PtM, M=Ni, Fe, Co) alloys catalysts show high oxygen reduction reaction (ORR) activity due to their well-known strain and ligand effects. However, these PtM alloys usually suffer from a deficient ORR durability in acidic environment as the alloyed metal is prone to be dissolved due to its high electronegativity. Herein, we report a new class of PtMn alloy nanodendrite catalyst with low-electronegativity Mn-contraction for boosting the oxygen reduction durability of fuel cells. The moderate strain in PtMn, induced by Mn contraction, yields optimal oxygen reduction activity at 0.53 A mg-1 at 0.9 V versus reversible hydrogen electrode (RHE). Most importantly, we show that relative to well-known high-electronegativity Ni-based Pt alloy counterpart, the PtMn nanodendrite catalyst experiences less transition metals' dissolution in acidic solution and achieves an outstanding mass activity retention of 96 % after 10,000 degradation cycles. Density functional theory calculation reveals that PtMn alloys are thermodynamically more stable than PtNi alloys in terms of formation enthalpy and cohesive energy. The PtMn nanodendrite-based membrane electrode assembly delivers an outstanding peak power density of 1.36 W cm-2 at a low Pt loading and high-performance retention over 50 h operations at 0.6 V in H2 -O2 hydrogen fuel cells.
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Affiliation(s)
- Yan Nie
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
- School of Chemistry, University of New South Wales, Sydney, 2052, Australia
| | - Yingjun Sun
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Bingyi Song
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Quentin Meyer
- School of Chemistry, University of New South Wales, Sydney, 2052, Australia
| | - Shiyang Liu
- School of Chemistry, University of New South Wales, Sydney, 2052, Australia
| | - Hongyu Guo
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Lu Tao
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Fangxu Lin
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Mingchuan Luo
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Liming Yang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Chuan Zhao
- School of Chemistry, University of New South Wales, Sydney, 2052, Australia
| | - Shaojun Guo
- School of Materials Science and Engineering, Peking University, Beijing, 100871, China
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Meyer Q, Yang C, Cheng Y, Zhao C. Overcoming the Electrode Challenges of High-Temperature Proton Exchange Membrane Fuel Cells. ELECTROCHEM ENERGY R 2023. [DOI: 10.1007/s41918-023-00180-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
AbstractProton exchange membrane fuel cells (PEMFCs) are becoming a major part of a greener and more sustainable future. However, the costs of high-purity hydrogen and noble metal catalysts alongside the complexity of the PEMFC system severely hamper their commercialization. Operating PEMFCs at high temperatures (HT-PEMFCs, above 120 °C) brings several advantages, such as increased tolerance to contaminants, more affordable catalysts, and operations without liquid water, hence considerably simplifying the system. While recent progresses in proton exchange membranes for HT-PEMFCs have made this technology more viable, the HT-PEMFC viscous acid electrolyte lowers the active site utilization by unevenly diffusing into the catalyst layer while it acutely poisons the catalytic sites. In recent years, the synthesis of platinum group metal (PGM) and PGM-free catalysts with higher acid tolerance and phosphate-promoted oxygen reduction reaction, in conjunction with the design of catalyst layers with improved acid distribution and more triple-phase boundaries, has provided great opportunities for more efficient HT-PEMFCs. The progress in these two interconnected fields is reviewed here, with recommendations for the most promising routes worthy of further investigation. Using these approaches, the performance and durability of HT-PEMFCs will be significantly improved.
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Müller-Hülstede J, Uhlig LM, Schmies H, Schonvogel D, Meyer Q, Nie Y, Zhao C, Vidakovic J, Wagner P. Towards the Reduction of Pt Loading in High Temperature Proton Exchange Membrane Fuel Cells - Effect of Fe-N-C in Pt-Alloy Cathodes. ChemSusChem 2023; 16:e202202046. [PMID: 36484108 DOI: 10.1002/cssc.202202046] [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] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/08/2022] [Indexed: 06/17/2023]
Abstract
Pt poisoning by phosphate in high temperature proton exchange membrane fuel cells (HT-PEMFC) leads to loadings up to 1 mgPt cm-2 per electrode of costly materials. While cheaper Fe-N-C catalysts are unaffected by phosphate deactivation and contribute to the catalysis of the oxygen reduction reaction, their volumetric activity is substantially lower. In this study, the effect of Pt-loading reduced hybrid cathodes for HT-PEMFC is investigated using commercial Celtec®-P-based assembling. A promising effect of Fe-N-C incorporation in terms of acid attraction and activity retention is found. A longer activation (230 h, 0.3 A cm-2 ) for the hybrid membrane electrode assembly (MEA) is necessary, due to the slower acid distribution within Fe-N-Cs. This study shows the potential of Pt-content reduction by up to 25 % compared to standard MEA using hybrid electrodes. Moreover, important insights for future strategies of cell activation are revealed for these hybrid MEAs.
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Affiliation(s)
- Julia Müller-Hülstede
- Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Carl-von-Ossietzky-Str. 15, 26129, Oldenburg, Germany
| | - Lisa M Uhlig
- Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Carl-von-Ossietzky-Str. 15, 26129, Oldenburg, Germany
| | - Henrike Schmies
- Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Carl-von-Ossietzky-Str. 15, 26129, Oldenburg, Germany
| | - Dana Schonvogel
- Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Carl-von-Ossietzky-Str. 15, 26129, Oldenburg, Germany
| | - Quentin Meyer
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Yan Nie
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | | | - Peter Wagner
- Institute of Engineering Thermodynamics, German Aerospace Center (DLR), Carl-von-Ossietzky-Str. 15, 26129, Oldenburg, Germany
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Wang YD, Meyer Q, Tang K, McClure JE, White RT, Kelly ST, Crawford MM, Iacoviello F, Brett DJL, Shearing PR, Mostaghimi P, Zhao C, Armstrong RT. Large-scale physically accurate modelling of real proton exchange membrane fuel cell with deep learning. Nat Commun 2023; 14:745. [PMID: 36788206 PMCID: PMC9929041 DOI: 10.1038/s41467-023-35973-8] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/10/2023] [Indexed: 02/16/2023] Open
Abstract
Proton exchange membrane fuel cells, consuming hydrogen and oxygen to generate clean electricity and water, suffer acute liquid water challenges. Accurate liquid water modelling is inherently challenging due to the multi-phase, multi-component, reactive dynamics within multi-scale, multi-layered porous media. In addition, currently inadequate imaging and modelling capabilities are limiting simulations to small areas (<1 mm2) or simplified architectures. Herein, an advancement in water modelling is achieved using X-ray micro-computed tomography, deep learned super-resolution, multi-label segmentation, and direct multi-phase simulation. The resulting image is the most resolved domain (16 mm2 with 700 nm voxel resolution) and the largest direct multi-phase flow simulation of a fuel cell. This generalisable approach unveils multi-scale water clustering and transport mechanisms over large dry and flooded areas in the gas diffusion layer and flow fields, paving the way for next generation proton exchange membrane fuel cells with optimised structures and wettabilities.
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Affiliation(s)
- Ying Da Wang
- grid.1005.40000 0004 4902 0432School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, NSW 2052 Australia
| | - Quentin Meyer
- School of Chemistry, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Kunning Tang
- grid.1005.40000 0004 4902 0432School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, NSW 2052 Australia
| | - James E. McClure
- grid.438526.e0000 0001 0694 4940National Security Institute, Virginia Tech, Blacksburg, VA 24061 USA
| | - Robin T. White
- Carl Zeiss X-ray Microscopy, ZEISS Innovation Center California, Dublin, CA 94568 USA
| | - Stephen T. Kelly
- Carl Zeiss X-ray Microscopy, ZEISS Innovation Center California, Dublin, CA 94568 USA
| | | | - Francesco Iacoviello
- grid.83440.3b0000000121901201Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE UK
| | - Dan J. L. Brett
- grid.83440.3b0000000121901201Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE UK
| | - Paul R. Shearing
- grid.83440.3b0000000121901201Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE UK
| | - Peyman Mostaghimi
- grid.1005.40000 0004 4902 0432School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, NSW 2052 Australia
| | - Chuan Zhao
- School of Chemistry, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Ryan T. Armstrong
- grid.1005.40000 0004 4902 0432School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, NSW 2052 Australia
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Dastafkan K, Shen X, Hocking RK, Meyer Q, Zhao C. Monometallic interphasic synergy via nano-hetero-interfacing for hydrogen evolution in alkaline electrolytes. Nat Commun 2023; 14:547. [PMID: 36725848 PMCID: PMC9892594 DOI: 10.1038/s41467-023-36100-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/16/2023] [Indexed: 02/03/2023] Open
Abstract
Electrocatalytic synergy is a functional yet underrated concept in electrocatalysis. Often, it materializes as intermetallic interaction between different metals. We demonstrate interphasic synergy in monometallic structures is as much effective. An interphasic synergy between Ni(OH)2 and Ni-N/Ni-C phases is reported for alkaline hydrogen evolution reaction that lowers the energy barriers for hydrogen adsorption-desorption and facilitates that of hydroxyl intermediates. This makes ready-to-serve Ni active sites and allocates a large amount of Ni d-states at Fermi level to promote charge redistribution from Ni(OH)2 to Ni-N/Ni-C and the co-adsorption of Hads and OHads intermediates on Ni-N/Ni-C moieties. As a result, a Ni(OH)2@Ni-N/Ni-C hetero-hierarchical nanostructure is developed, lowering the overpotentials to deliver -10 and -100 mA cm-2 in alkaline media by 102 and 113 mV, respectively, compared to monophasic Ni(OH)2 catalyst. This study unveils the interphasic synergy as an effective strategy to design monometallic electrocatalysts for water splitting and other energy applications.
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Affiliation(s)
- Kamran Dastafkan
- grid.1005.40000 0004 4902 0432School of Chemistry, UNSW Materials and Manufacturing Futures Institute, The University of New South Wales, Sydney, New South Wales 2052 Australia
| | - Xiangjian Shen
- grid.207374.50000 0001 2189 3846Engineering Research Center of Advanced Functional Material Manufacturing of Ministry of Education, Zhengzhou University, Zhengzhou, 450001 China
| | - Rosalie K. Hocking
- grid.1027.40000 0004 0409 2862Department of Chemistry and Biotechnology, Centre for Translational Atomaterials and ARC Training Centre for Surface Engineering for Advanced Material SEAM, Swinburne University of Technology, Hawthorn, VIC 3122 Australia
| | - Quentin Meyer
- grid.1005.40000 0004 4902 0432School of Chemistry, UNSW Materials and Manufacturing Futures Institute, The University of New South Wales, Sydney, New South Wales 2052 Australia
| | - Chuan Zhao
- grid.1005.40000 0004 4902 0432School of Chemistry, UNSW Materials and Manufacturing Futures Institute, The University of New South Wales, Sydney, New South Wales 2052 Australia
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Chen Y, Zeng X, Meyer Q, Zhao C, He Z, Wu F, Tang H, Cheng Y. An outstanding NiFe/NF oxygen evolution reaction boosted by the hydroxyl oxides. Electrochim Acta 2023. [DOI: 10.1016/j.electacta.2023.141862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Quattrocchi E, Py B, Maradesa A, Meyer Q, Zhao C, Ciucci F. Deconvolution of Electrochemical Impedance Spectroscopy Data Using the Deep-Neural-Network-Enhanced Distribution of Relaxation Times. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Tang K, Meyer Q, White R, Armstrong RT, Mostaghimi P, Da Wang Y, Liu S, Zhao C, Regenauer-Lieb K, Tung PKM. Deep learning for full-feature X-ray microcomputed tomography segmentation of proton electron membrane fuel cells. Comput Chem Eng 2022. [DOI: 10.1016/j.compchemeng.2022.107768] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Liu S, Meyer Q, Li Y, Zhao T, Su Z, Ching K, Zhao C. Fe-N-C/Fe nanoparticle composite catalysts for the oxygen reduction reaction in proton exchange membrane fuel cells. Chem Commun (Camb) 2022; 58:2323-2326. [PMID: 35076040 DOI: 10.1039/d1cc07042h] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Replacing Pt-based catalysts with cost-effective, highly efficient, and durable platinum group metal-free catalysts for the oxygen reduction reaction (ORR) is crucial for commercializing hydrogen fuel cells. Herein, we present a highly active Fe-N-C electrocatalyst that contains both Fe nanoparticles and FeNx active sites derived from an Fe-doped carbonized zeolitic imidazolate framework (ZIF-8). It is found that adjusting the doping amount of Fe in the Fe-doped ZIF-8 precursor alters the morphology of the catalyst after heat treatment. The Fe-N-C-300 composite catalyst with the optimized Fe doping amount exhibits excellent activity, good stability, and remarkable methanol tolerance in the challenging acid environment. This study reveals that a suitable amount of Fe nanoparticles in the catalyst can alter the structure of the FeNx active moieties and increase three-phase boundaries to boost the mass transport, thus leading to improved fuel cell performance. This will have implications for using Fe-N-C catalysts in real applications, as the formation of Fe NPs during the synthesis and reaction is almost inevitable.
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Affiliation(s)
- Shiyang Liu
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Quentin Meyer
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Yibing Li
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Tingwen Zhao
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Zhen Su
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Karin Ching
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
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Dastafkan K, Meyer Q, Chen X, Zhao C. Efficient Oxygen Evolution and Gas Bubble Release Achieved by a Low Gas Bubble Adhesive Iron-Nickel Vanadate Electrocatalyst. Small 2020; 16:e2002412. [PMID: 32627936 DOI: 10.1002/smll.202002412] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/03/2020] [Indexed: 06/11/2023]
Abstract
Surface chemistry is a pivotal prerequisite besides catalyst composition toward advanced water electrolysis. Here, an evident enhancement of the oxygen evolution reaction (OER) is demonstrated on a vanadate-modified iron-nickel catalyst synthesized by a successive ionic layer adsorption and reaction method, which demonstrates ultralow overpotentials of 274 and 310 mV for delivering large current densities of 100 and 400 mA cm-2 , respectively, in 1 m KOH, where vigorous gas bubble evolution occurs. Vanadate modification augments the OER activity by i) increasing the electrochemical surface area and intrinsic activity of the active sites, ii) having an electronic interplay with Fe and Ni catalytic centers, and iii) inducing a high surface wettability and a low-gas bubble-adhesion for accelerated mass transport and gas bubble dissipation at large current densities. Ex situ and operando Raman study reveals the structural evolution of β-NiOOH and γ-FeOOH phases during the OER through vanadate-active site synergistic interactions. Operando dynamic specific resistance measurement evidences an accelerated gas bubble dissipation by a significant decrease in the variation of the interfacial resistance during the OER for the vanadate-modified surface. Achievement of a high catalytic turnover of 0.12 s-1 suggests metallic oxo-anion modification as a versatile catalyst design strategy for advanced water oxidation.
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Affiliation(s)
- Kamran Dastafkan
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Quentin Meyer
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Xianjue Chen
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia
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Meyer Q, Zeng Y, Zhao C. In Situ and Operando Characterization of Proton Exchange Membrane Fuel Cells. Adv Mater 2019; 31:e1901900. [PMID: 31373051 DOI: 10.1002/adma.201901900] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/06/2019] [Indexed: 06/10/2023]
Abstract
For proton exchange membrane fuel cells (PEMFCs) to become a mainstream energy source, significant improvements in their performance, durability, and efficiency are necessary. To improve their durability, there must be a solid understanding of how the structural and electrochemical processes are affected during operation to propose mitigation strategies. To this aim, in situ and operando characterization techniques can locally identify structural and electrochemical processes, which cannot be captured using conventional techniques. Linking these properties in the same geometric area has been challenging due to its inherent limitations, such as sample size and imaging resolution. This has created a knowledge gap in structure-to-electrochemical performance relationships as operation and degradation unevenly affect different areas of the cell. In the recent past, catalyst layer degradation, hot spots, and water management have been structurally and electrochemically visualized in the same geometric area, revealing new interactions. To further the research in this direction, these interconnected fields are reviewed, followed by a roadmap for in situ characterization of PEMFCs, treating structural and electrochemical processes as a unified subject. With this approach, the knowledge of the degradation of PEMFCs will be significantly improved.
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Affiliation(s)
- Quentin Meyer
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Yachao Zeng
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Chuan Zhao
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
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Meyer Q, Mansor N, Iacoviello F, Cullen P, Jervis R, Finegan D, Tan C, Bailey J, Shearing P, Brett D. Investigation of Hot Pressed Polymer Electrolyte Fuel Cell Assemblies via X-ray Computed Tomography. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.05.028] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Meyer Q, Ashton S, Torija S, Gurney C, Boillat P, Cochet M, Engebretsen E, Finegan DP, Adcock P, Shearing PR, Brett DJ. Nitrogen Blanketing and Hydrogen Starvation in Dead-Ended-Anode Polymer Electrolyte Fuel Cells Revealed by Hydro-Electro-Thermal Analysis. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.04.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Meyer Q, Barass S, Curnick O, Reisch T, Brett DJ. A multichannel frequency response analyser for impedance spectroscopy on power sources. J Electrochem Sci Eng 2013. [DOI: 10.5599/jese.2013.0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Abstract
With the rapid development of powerful protein evolution and enzyme-screening technologies, there is a growing belief that optimum conditions for biotransformation processes can be established without the constraints of the properties of the biocatalyst. These technologies can then be applied to find the ‘ideal biocatalyst’ for the process. In identifying the ideal biocatalyst, the processes of gene discovery and enzyme evolution play major roles. However, in order to expand the pool genes for in vitro evolution, new technologies, which circumvent the limitations of microbial culturability, must be applied. These technologies, which currently include metagenomic library screening, gene-specific amplification methods and even full metagenomic sequencing, provide access to a volume of ‘sequence space’ that is not addressed by traditional screening.
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Affiliation(s)
- D A Cowan
- Advanced Research Centre for Applied Microbiology, Department of Biotechnology, University of the Western Cape, Bellville 7535, Cape Town, South Africa.
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Woodle M, Huang S, Meyer Q, Brown B, Dizik M, Hong K, Papahadjopoulos D. Oligonucleotide therapeutics: lessons from sterically stabilized liposomes. Adv Drug Deliv Rev 1997. [DOI: 10.1016/s0169-409x(96)00468-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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