New roads and challenges for fuel cells in heavy-duty transportation

Cullen, David A.; Neyerlin, Kenneth C.; Ahluwalia, R.K.; Mukundan, Rangachary; More, Karren L.; Borup, Rodney L.; Weber, Adam Z.; Myers, Deborah J.; Kusoglu, Ahmet

doi:10.1038/s41560-021-00775-z

Cited by 688 publications

(512 citation statements)

References 82 publications

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“…Motivated by these demands, the US DRIVE Fuel Cell Tech Team has set a 2025 power density target of 1.8 W cm −2 10 , and the New Energy and Industrial Technology Development Organization in Japan recently set a 2030 power density target of 2.5 W cm −2 with 0.12–0.25 mg cm −2 Pt loading 11 . In addition, Million Mile Fuel Cell Truck (M2FCT) consortium has set a 2025 efficiency and durability target of 2.5 kW g PGM −1 power (1.07 A cm −2 current density) at 0.7 V after 25,000 hour-equivalent accelerated durability test for heavy-duty vehicle applications 12 , 13 .…”

Section: Introductionmentioning

confidence: 99%

The role of oxygen-permeable ionomer for polymer electrolyte fuel cells

et al. 2021

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In recent years, considerable research and development efforts are devoted to improving the performance of polymer electrolyte fuel cells. However, the power density and catalytic activities of these energy conversion devices are still far from being satisfactory for large-scale operation. Here we report performance enhancement via incorporation, in the cathode catalyst layers, of a ring-structured backbone matrix into ionomers. Electrochemical characterizations of single cells and microelectrodes reveal that high power density is obtained using an ionomer with high oxygen solubility. The high solubility allows oxygen to permeate the ionomer/catalyst interface and react with protons and electrons on the catalyst surfaces. Furthermore, characterizations of single cells and single-crystal surfaces reveal that the oxygen reduction reaction activity is enhanced owing to the mitigation of catalyst poisoning by sulfonate anion groups. Molecular dynamics simulations indicate that both the high permeation and poisoning mitigation are due to the suppression of densely layered folding of polymer backbones near the catalyst surfaces by the incorporated ring-structured matrix. These experimental and theoretical observations demonstrate that ionomer’s tailored molecular design promotes local oxygen transport and catalytic reactions.

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Section: Introductionmentioning

confidence: 99%

The role of oxygen-permeable ionomer for polymer electrolyte fuel cells

et al. 2021

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“…This will in contrast to passenger LDVs (with expected cathode loadings of 0.1 mgPt cm -2 or lower) suit better the application of Pt-alloys in HDVs (with expected cathode loadings of 0.25 mgPt cm -2 ). 4 Furthermore, heavier transport applications in general, could significantly benefit from limiting both the upper and lower voltage limits 48 and significantly increase the life as well as the long-term performance of the PEMFC stack. Following the assessment of various potential windows at a constant temperature of 75 o C in Figure 2, we are now focusing only on the potential window that is still most typically used in the literature (several thousands of cycles between 0.6-1 VRHE) and often referred to as the 'operating conditions'.…”

Section: Resultsmentioning

confidence: 99%

“…While electrocatalyst stability is of general importance, its significance becomes even more decisive for their application in HDVsresulting from in-average longer travel distances in comparison to passenger LDVs and thus, significantly higher system lifetime requirements. 4 Because the degradation of Pt-alloy electrocatalysts is caused by various extremely complicated phenomena, 19 significant efforts have to be invested into clarifying and understanding individual mechanisms. There are two basic groups of degradation mechanisms: i) electrochemically-induced (transient) dissolution of Pt, which is closely related with the dynamics of formation/reduction of the Pt-oxide 20 , resulting in Ostwald ripening 21 and/or formation of metallic Pt bands in the membrane 22 ; ii) electrochemical and chemical carbon support corrosion 23 , leading to the agglomeration 24 and/or detachment 19 of Pt NPs.…”

Section: Introductionmentioning

confidence: 99%

Understanding the Crucial Significance of the Temperature and Potential Window on the Stability of Carbon Supported Pt-alloy Nanoparticles as Oxygen Reduction Reaction Electrocatalysts

Đukić

Moriau

Pavko

et al. 2021

Preprint

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The present research provides a comprehensive study of carbon-supported intermetallic Pt-alloy electrocatalysts and assesses their stability against metal dissolution in relation to the operating temperature and the potential window using two advanced electrochemical methodologies: (i) the in-house designed high-temperature disk electrode (HT-DE) methodology as well as (ii) a modification of the electrochemical flow cell coupled to an inductively coupled plasma mass spectrometer (EFC-ICP-MS), allowing for highly sensitive time- and potential-resolved measurements of metal dissolution. The findings contradict the generally accepted hypothesis that in contrast to the rate of carbon corrosion, which follows the Arrhenius law and increases exponentially with temperature, the kinetics of Pt and subsequently the less noble metal dissolution are supposed to be for the most part unaffected by temperature. On the contrary, clear evidence is presented that in addition to the importance of the voltage/potential window, the temperature is one of the most critical parameters governing the stability of Pt and thus, in the case of Pt-alloy electrocatalysts also the ability of the nanoparticles (NPs) to retain the less noble metal. Lastly, but also very importantly, results indicate that the rate of Pt redeposition significantly increases with temperature, which has been the main reason why mechanistic interpretation of the temperature-dependent kinetics related to the stability of Pt remained highly speculative until now.

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“…They also influence emerging battery and fuel cell technologies, which are usually – thermally or electrically – energy‐intensive. [ 21–23 ] Thus, such technologies harness catalysis to reduce reaction temperatures, pressures, or electrochemical overpotentials. With regard to overcoming such technological limitations, single‐atom catalysts (SACs) are highly promising, featuring active and isolated single metal atoms stabilized by supportive substrates or alloying.…”

Section: Introductionmentioning

confidence: 99%

Engineering Single Atom Catalysts to Tune Properties for Electrochemical Reduction and Evolution Reactions

Maiti

Curnan

et al. 2021

Advanced Energy Materials

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Electrocatalysis is important to the conversion and storage of renewable energy resources, including fuel cells, water electrolysers, and batteries. Engineering metal‐based nano‐architectures and their atomic‐scale surfaces is a promising approach for designing electrocatalysts. Single metal atom interactions with substrates and reaction environments crucially modulate the surface electronic properties of active metal centers, yielding controllable scaling relationships and transitions between different reaction mechanisms that improve catalytic activity. Single‐atom catalysts (SACs) allow activity and selectivity tuning while maintaining relatively consistent morphologies. SACs have well‐defined configurations and active centers within homogeneous single‐atom dispersions, producing exceptional selectivities, activities, and stabilities. Furthermore, SACs with high per‐atom utilization efficiencies, well‐controlled substrate compositions, and engineered surface structures develop single atom active sites for molecular reactions, enhancing mass activities. Recent developments in different metal‐based SAC nanostructures are discussed to explain their remarkable bi‐functional electrocatalytic activities and high mechanical flexibility, especially in the oxygen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, hydrogen evolution reaction, and in battery applications. Existing barriers to and future insights into improving SAC performance are addressed. This study develops practical and fundamental insights on single atom electrocatalysts directed towards tuning their electrocatalytic activities and enhancing their stabilities.

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New roads and challenges for fuel cells in heavy-duty transportation

Cited by 688 publications

References 82 publications

The role of oxygen-permeable ionomer for polymer electrolyte fuel cells

The role of oxygen-permeable ionomer for polymer electrolyte fuel cells

Understanding the Crucial Significance of the Temperature and Potential Window on the Stability of Carbon Supported Pt-alloy Nanoparticles as Oxygen Reduction Reaction Electrocatalysts

Engineering Single Atom Catalysts to Tune Properties for Electrochemical Reduction and Evolution Reactions

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