Binaphthyl-based molecular barrier materials for phosphoric acid poisoning in high-temperature proton exchange membrane fuel cells

Jeong, Dong−Cheol; Mun, Bohyun; Lee, Hyekyung; Hwang, Seung Jun; Yoo, Sung Jong; Cho, EunAe; Lee, Yun-Mi; Song, Changsik

doi:10.1039/c6ra13123a

Cited by 13 publications

(9 citation statements)

References 24 publications

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“…A good interaction between the catalyst and such an organic additive can play a vital role in enhancing the efficiency and in decreasing PA poisoning of the fuel cell catalyst . Several groups examined various additives either added to the electrolyte or directly bound to the catalyst surface to improve the ORR and avoid poisoning of the Pt active sites . A recent study by Zeis and co‐workers showed that perfluoralkylated PAs used as electrolyte additives improved ORR kinetics on polycrystalline Pt .…”

Section: Introductionmentioning

confidence: 99%

“…The cyanide ions successfully prevented undesirable ions from binding at the electrode surface, allowing the ORR to proceed unhindered . Recently, Song and co‐workers investigated thiol‐functionalized binaphthyl additives to prevent phosphate species poisoning in HT‐PEMFC . They reported that the Pt catalyst was simply dipped in a terahydrofuran (THF) solution of the additive resulting in an improved ORR activity of Pt nanoparticles in the presence of PA.…”

Section: Introductionmentioning

confidence: 99%

“…To modify and therefore functionalize the carbon electrode polycyclic aromatic hydrocarbons (PAHs), like the binaphthyl additive of Song et al., are preferable additives in HT‐PEMFC, because of their high chemical, thermal (decomposition at 600 °C) and mechanical stability. [36] Furthermore, PAHs interact with the catalyst support via π‐π interaction .…”

Section: Introductionmentioning

confidence: 99%

“…[28] Several groups examined various additives either added to the electrolyte or directly bound to the catalyst surface to improve the ORR and avoid poisoning of the Pt active sites. [29][30][31][32][33][34] A recent study by Zeis and co-workers showed that perfluoralkylated PAs used as electrolyte additives improved ORR kinetics on polycrystalline Pt. [34,35] Cuesta et al investigated how coating the platinum catalyst surface with cyanide ions through coordination affected the catalyst activity.…”

Section: Introductionmentioning

confidence: 99%

“…[36] Furthermore, PAHs interact with the catalyst support via π‐π interaction . Inspired by the work of the Song group, we have developed two new additives that were also supposed to prevent the undesired binding of PA anions to the Pt surface, while the ORR should be unaffected and unhindered. In this work, we present a PAH with a large π‐network and variable substitutable positions to interact with the components of the PEMFC (i. e. Pt nanoparticle catalyst, carbon support, PA electrolyte) and therefore stabilize and improve the HT‐PEMFC performance.…”

Section: Introductionmentioning

confidence: 99%

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Organic Additives to Improve Catalyst Performance for High‐Temperature Polymer Electrolyte Membrane Fuel Cells

et al. 2019

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High‐temperature polymer electrolyte membrane fuel cells are promising alternatives to low temperature fuel cells, owing to their higher operating temperatures, which allow for easier water management and enhanced catalytic activity. However, their performance suffers from low oxygen solubility in the electrolyte and phosphoric acid poisoning of catalytically active Pt sites. In this work, we developed new organic additives that provide π‐π stacking of the commercially applied carbon support materials as well as variable substitutable functionalities to interact with the Pt nanoparticles. Different electrochemical methods, such as cyclic voltammetry and linear sweep voltammetry, were performed to test the effect of these organic additives on the onset potential, limiting current, and the number of transferred electrons. It is observed that the limiting currents increase for the additive‐modified Pt/C samples, whereas the onset potential for significant oxygen reduction reaction activity remains unchanged. We conclude that enhanced oxygen solubility at the electrode/electrolyte interface is the reason for the observed behavior.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Organic Additives to Improve Catalyst Performance for High‐Temperature Polymer Electrolyte Membrane Fuel Cells

et al. 2019

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Antipoisoning catalysts for the selective oxygen reduction reaction at the interface between metal nanoparticles and the electrolyte

et al. 2023

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One of the primary challenges in relation to phosphoric acid fuel cells is catalyst poisoning by phosphate anions that occurs at the interface between metal nanoparticles and the electrolyte. The strong adsorption of phosphate anions on the catalyst surface limits the active sites for the oxygen reduction reaction (ORR), significantly deteriorating fuel cell performance. Here, antipoisoning catalysts consisting of Pt-based nanoparticles encapsulated in an ultrathin carbon shell that can be used as a molecular sieve layer are rationally designed. The pore structure of the carbon shells is systematically regulated at the atomic level by high-temperature gas treatment, allowing O 2 molecules to selectively react on the active sites of the metal nanoparticles through the molecular sieves. Besides, the carbon shell, as a protective layer, effectively prevents metal dissolution from the catalyst during a long-term operation. Consequently, the defect-controlled carbon shell leads to outstanding ORR activity and durability of the hybrid catalyst even in phosphoric acid electrolytes.

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Micropore‐Rich Carbon‐Confined Pt as the Phosphoric Acid Poisoning‐Resistant Electrocatalyst for Oxygen Reduction Reaction

Zhang

et al. 2023

Energy Tech

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The H3PO4 poisoning problem severely limits the performance of high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs) using the H3PO4‐doped polybenzimidazole as electrolyte membrane. Herein, the micropore‐rich carbon shell‐confined Pt‐based nanoparticles (Pt@MPC) with a Pt loading of 44.9 wt% is developed as the H3PO4 poisoning‐resistant electrocatalyst for oxygen reduction reaction (ORR), which possesses both high ORR activity and stability. The half‐wave potential (E1/2) of 0.898 V and electrochemical active surface area (ECSA) of 62.3 m2 gPt−1 are superior to commercial 40 wt% Pt/C (E1/2 = 0.892 V; ECSA = 53.1 m2 gPt−1). Pt@MPC remains almost unchanged after the accelerated durability test of 10 000 cycles. Moreover, Pt@MPC exhibits remarkable H3PO4 tolerance as its negative shift of E1/2 (82 mV) is less in H3PO4‐containing electrolyte compared with commercial Pt/C (114 mV). This can be attributed to the steric effect of the micropore‐rich carbon, which enables the selective transport of reactants while inhibiting H3PO4. The HT‐PEMFCs assembled with Pt@MPC (0.7 mgPt cm−2) exhibit a maximum power density of 674 mW cm−2 under the H2‐O2 condition and outperform the commercial Pt/C (616 mW cm−2). This strategy provides a new direction for the design of ORR catalysts toward HT‐PEMFCs with better phosphoric acid poisoning resistance.

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Binaphthyl-based molecular barrier materials for phosphoric acid poisoning in high-temperature proton exchange membrane fuel cells

Abstract: In this study, thiol-functionalized binaphthyl barrier molecules were designed and synthesized for eliminating phosphoric acid (PA)-poisoning on Pt catalysts in oxygen reduction reactions (ORRs).

Cited by 13 publications

References 24 publications

Organic Additives to Improve Catalyst Performance for High‐Temperature Polymer Electrolyte Membrane Fuel Cells

Organic Additives to Improve Catalyst Performance for High‐Temperature Polymer Electrolyte Membrane Fuel Cells

Antipoisoning catalysts for the selective oxygen reduction reaction at the interface between metal nanoparticles and the electrolyte

Micropore‐Rich Carbon‐Confined Pt as the Phosphoric Acid Poisoning‐Resistant Electrocatalyst for Oxygen Reduction Reaction

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