Catalyst layers in proton exchange membrane fuel cells consist of platinum-group-metal nanocatalysts supported on carbon aggregates, forming a porous structure through which an ionomer network percolates. The local structural character of these heterogeneous assemblies is directly linked to the mass-transport resistances and subsequent cell performance losses; its three-dimensional visualization is therefore of interest. Herein we implement deep-learning-aided cryogenic transmission electron tomography for image restoration, and we quantitatively investigate the full morphology of various catalyst layers at the local-reaction-site scale. The analysis enables computation of metrics such as the ionomer morphology, coverage and homogeneity, location of platinum on the carbon supports, and platinum accessibility to the ionomer network, with the results directly compared and validated with experimental measurements. We expect that our findings and methodology for evaluating catalyst layer architectures will contribute towards linking the morphology to transport properties and overall fuel cell performance.
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http://dx.doi.org/10.1038/s41929-023-00947-y | DOI Listing |
ACS Catal
January 2025
Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague 8, Czech Republic.
Achieving the optimal balance between cost-efficiency and stability of oxygen reduction reaction (ORR) catalysts is currently among the key research focuses aiming at reaching a broader implementation of proton-exchange membrane fuel cells (PEMFCs). To address this challenge, we combine two well-established strategies to enhance both activity and stability of platinum-based ORR catalysts. Specifically, we prepare ternary PtNi-Au alloys, where each alloying element plays a distinct role: Ni reduces costs and boosts ORR activity, while Au enhances stability.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Southern Laboratories-208A, Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
The replacement of the thermodynamically unfavorable anodic oxygen evolution reaction (OER) with a more favorable organic oxidation reaction, such as the anodic oxidation of benzylamine, has garnered significant interest in hybrid water electrolyzer cells. This approach promises the production of value-added chemicals alongside hydrogen fuel generation, improving overall energy efficiency. However, achieving high current density for benzylamine oxidation without interference from OER remains a challenge, limiting the practical efficiency of the electrolyzer cell.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Jiao Tong University, School of Environmental Science and Engineering, 800 Dongchuan Road, 200240, Shanghai, CHINA.
Achieving high product selectivity at ampere-level current densities is essential for the industrial application of electrochemical CO2 reduction. However, the operational stability of CO2 electrolyzers at large current density has long been hindered by flooding of gas diffusion layer (GDL). Herein, a new heteroarchitectural GDL is designed to overcome flooding.
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January 2025
Graduate School of Energy Convergence, Institute of Integrated Technology, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
This study explores improving proton exchange membrane water electrolysis (PEMWE) by achieving both cost-effectiveness and enhanced efficiency through the replacement of the costly and environmentally challenging Nafion ionomer with hydroxypropyl methylcellulose (HPMC) as an anode binder. HPMC, an eco-friendly and cost-effective material, was cross-linked with citric acid to form a durable hydrogel that enhances water and proton transport within the catalyst layer. Using the cross-linked HPMC binder allowed a reduction in cost to 1/54 compared to Nafion ionomer, while the performance of the cross-linked HPMC electrodes remained comparable to Nafion electrodes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada.
One of the key technical challenges before the widespread adoption of proton exchange membrane fuel cells (PEMFCs) is increasing the durability of the platinum catalyst layer to meet a target of 8000 operating hours with only a 10% loss of performance. Carbon corrosion, one of the primary mechanisms of degradation in fuel cells, has attracted attention from researchers interested in solving the durability problem. As such, the development of catalyst supports to avoid this issue has been a focus in recent years, with interest in hydrophobic supports such as highly graphitized carbons.
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