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Grandi M, Gatalo M, Kamšek AR, Kapun G, Mayer K, Ruiz-Zepeda F, Šala M, Marius B, Bele M, Hodnik N, Bodner M, Gaberšček M, Hacker V. Mechanistic Study of Fast Performance Decay of PtCu Alloy-based Catalyst Layers for Polymer Electrolyte Fuel Cells through Electrochemical Impedance Spectroscopy. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093544. [PMID: 37176426 PMCID: PMC10180127 DOI: 10.3390/ma16093544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/06/2023] [Accepted: 04/17/2023] [Indexed: 05/15/2023]
Abstract
In the past, platinum-copper catalysts have proven to be highly active for the oxygen reduction reaction (ORR), but transferring the high activities measured in thin-film rotating disk electrodes (TF-RDEs) to high-performing membrane electrode assemblies (MEAs) has proven difficult due to stability issues during operation. High initial performance can be achieved. However, fast performance decay on a timescale of 24 h is induced by repeated voltage load steps with H2/air supplied. This performance decay is accelerated if high relative humidity (>60% RH) is set for a prolonged time and low voltages are applied during polarization. The reasons and possible solutions for this issue have been investigated by means of electrochemical impedance spectroscopy and distribution of relaxation time analysis (EIS-DRT). The affected electrochemical sub-processes have been identified by comparing the PtCu electrocatalyst with commercial Pt/C benchmark materials in homemade catalyst-coated membranes (CCMs). The proton transport resistance (Rpt) increased by a factor of ~2 compared to the benchmark materials. These results provide important insight into the challenges encountered with the de-alloyed PtCu/KB electrocatalyst during cell break-in and operation. This provides a basis for improvements in the catalysts' design and break-in procedures for the highly attractive PtCu/KB catalyst system.
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Affiliation(s)
- Maximilian Grandi
- Institute of Chemical Engineering and Environmental Technology, Graz University of Technology, Inffeldgasse 25/C, 8010 Graz, Austria
| | - Matija Gatalo
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Ana Rebeka Kamšek
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Gregor Kapun
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Kurt Mayer
- Institute of Chemical Engineering and Environmental Technology, Graz University of Technology, Inffeldgasse 25/C, 8010 Graz, Austria
| | - Francisco Ruiz-Zepeda
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Martin Šala
- Department of Analytical Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Bernhard Marius
- Institute of Chemical Engineering and Environmental Technology, Graz University of Technology, Inffeldgasse 25/C, 8010 Graz, Austria
| | - Marjan Bele
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Nejc Hodnik
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Merit Bodner
- Institute of Chemical Engineering and Environmental Technology, Graz University of Technology, Inffeldgasse 25/C, 8010 Graz, Austria
| | - Miran Gaberšček
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Viktor Hacker
- Institute of Chemical Engineering and Environmental Technology, Graz University of Technology, Inffeldgasse 25/C, 8010 Graz, Austria
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Kudashova DS, Falina IV, Kononenko NA, Demidenko KS. Physicochemical Properties and Performance Characteristics of Perfluorinated Membranes Bulk Modified with Platinum during Operation in Proton Exchange Membrane Fuel Cell. MEMBRANES AND MEMBRANE TECHNOLOGIES 2023. [DOI: 10.1134/s2517751623010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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Petriev I, Pushankina P, Shostak N, Baryshev M. Gas-Transport Characteristics of PdCu–Nb–PdCu Membranes Modified with Nanostructured Palladium Coating. Int J Mol Sci 2021; 23:ijms23010228. [PMID: 35008654 PMCID: PMC8745148 DOI: 10.3390/ijms23010228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 12/18/2021] [Accepted: 12/24/2021] [Indexed: 12/01/2022] Open
Abstract
A method for obtaining composite gas-diffusion PdCu–Nb–PdCu membranes modified with a nanostructured crystalline coating was developed to increase the performance of Nb-based membranes. A modifying functional layer with a controlled size and composition was synthesized by electrochemical deposition, which made it possible to determine a certain geometric shape for palladium nanocrystallites. Developed PdCu–Nb–PdCu membranes have demonstrated flux values up to 0.232 mmol s−1 m−2 in the processes of diffusion purification of hydrogen at 400 °C. A very significant difference in the hydrogen fluxes through the modified and non-modified composite PdCu–Nb–PdCu membranes reached 1.73 times at the lower threshold temperature of 300 °C. Cu doping of protective layer did not affect the selective properties of the membranes, which was confirmed by the obtained high selectivity values up to 1323, and made it possible to reduce the noble metal content. The research data indicate that the modification of the membrane surface significantly accelerates the hydrogen transfer process at sufficiently low temperatures due to the acceleration of dissociative–associative processes on the surface. The reported approach demonstrates new possibilities for creating productive and cost-efficient membranes based on niobium.
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Affiliation(s)
- Iliya Petriev
- Department of Physics, Kuban State University, 350040 Krasnodar, Russia; (P.P.); (M.B.)
- Laboratory of Problems of Stable Isotope Spreading in Living Systems, Southern Scientific Centre of the RAS, 344000 Rostov-on-Don, Russia
- Department of Oil and Gas Business, Kuban State Technological University, 350040 Krasnodar, Russia;
- Correspondence:
| | - Polina Pushankina
- Department of Physics, Kuban State University, 350040 Krasnodar, Russia; (P.P.); (M.B.)
- Department of Oil and Gas Business, Kuban State Technological University, 350040 Krasnodar, Russia;
| | - Nikita Shostak
- Department of Oil and Gas Business, Kuban State Technological University, 350040 Krasnodar, Russia;
| | - Mikhail Baryshev
- Department of Physics, Kuban State University, 350040 Krasnodar, Russia; (P.P.); (M.B.)
- Laboratory of Problems of Stable Isotope Spreading in Living Systems, Southern Scientific Centre of the RAS, 344000 Rostov-on-Don, Russia
- Department of Oil and Gas Business, Kuban State Technological University, 350040 Krasnodar, Russia;
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