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The long-standing challenges facing Pt-based alloy catalysts in oxygen reduction reactions (ORRs) are rapid oxidation and loss of transition metal/Pt in proton exchange membrane fuel cells (PEMFCs). In this work, we report a concept of "covalentization" in intermetallic L1-PtMM' (M = Fe, Co, Ni and M' = one of the 4-period elements (from Ti to Ge)) alloys to enhance their electrochemical stability. Specifically, the formation of a quasi-covalent bond network in L1-PtMM' due to the less occupied antibonding states induced by high d-band positions of M' elements (e.g., Ti, V, Cr) enhances atomic bond order and strength, diminishing Co anodic dissolution via strengthened Pt/Co-M' bonds and reducing Co cathodic corrosion by inhibiting Pt oxidation through an electron buffering effect. The developed L1-PtCoCr/C catalysts show a high mass activity (MA = 1.27 A mg) and rated power (16.5 W mg) in PEMFCs at a low total Pt loading of 0.075 mg cm. The catalysts also exhibit high electrochemical stability with ~3% and 5% loss of MA and rated power after 30,000 accelerated durability testing cycles and projects a lifetime of about 42,000 hours.
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http://dx.doi.org/10.1038/s41467-025-60171-z | DOI Listing |
Angew Chem Int Ed Engl
September 2025
State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
The sustainable and widespread developments of fuel cells require material innovation toward the sluggish oxygen reduction reaction (ORR). Although iron and nitrogen co-doped carbon material (Fe-N-C) is a promising alternative to scarce and expensive platinum-based electrocatalysts, the linear scaling relationships among the intermediates' adsorption energy limit maximum performance. Herein, we propose a coordination-adaptive catalyst design to bypass the intrinsic scaling relations through incorporating quasi-covalent Fe─F bond.
View Article and Find Full Text PDFNat Commun
May 2025
State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
The long-standing challenges facing Pt-based alloy catalysts in oxygen reduction reactions (ORRs) are rapid oxidation and loss of transition metal/Pt in proton exchange membrane fuel cells (PEMFCs). In this work, we report a concept of "covalentization" in intermetallic L1-PtMM' (M = Fe, Co, Ni and M' = one of the 4-period elements (from Ti to Ge)) alloys to enhance their electrochemical stability. Specifically, the formation of a quasi-covalent bond network in L1-PtMM' due to the less occupied antibonding states induced by high d-band positions of M' elements (e.
View Article and Find Full Text PDFPhys Chem Chem Phys
October 2023
College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, 201306, China.
To fully and deeply understand the weak interactions in the gaseous structure of the TKX-50 molecule, two conformations I and II of the TKX-50 molecule confirmed in a crystal cell were optimized at the B3LYP/6-311g(d,p) level in the gas state, and the single point energy of the optimized structure was calculated at the M06-2X/ma-TZVPP level. Analyzing methods for weak interactions such as the interaction region indicator (IRI), topological basin analysis, and the extended transition state-natural orbitals for chemical valence (ETS-NOCV) theory with the help of Multiwfn code were employed to reveal the corresponding intramolecular weak interactions. The results showed that there were 5 kinds of intramolecular weak interaction in both conformations.
View Article and Find Full Text PDFPhys Chem Chem Phys
March 2020
School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
Short, strong hydrogen bonds (SSHBs) have been a source of interest and considerable speculation over recent years, culminating with those where hydrogen resides around the midpoint between the donor and acceptor atoms, leading to quasi-covalent nature. We demonstrate that X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy provide deep insight into the electronic structure of the short OHN hydrogen bond of 3,5-pyridinedicarboxylic acid, revealing for the first time distinctive spectroscopic identifiers for these quasi-symmetrical hydrogen bonds. An intermediate nitrogen (core level) chemical shift occurs for the almost centrally located hydrogen compared to protonated (ionic) and non-ionic analogues, and it reveals the absence of two-site disorder.
View Article and Find Full Text PDFChem Commun (Camb)
March 2003
Laboratoire de Chimie de Coordination, UMR CNRS 7513, Université Louis Pasteur, 4 rue Blaise Pascal, F-67070 Strasbourg Cedex, France.
An unusual early-late bimetallic complex with direct metal-metal bonding is obtained from a phosphinoenolate ligand-assisted reaction between Ti(IV) and Pt(0) reagents which occurs by formal insertion of the Pt(0) centre into a Ti(IV)-O bond; X-ray data and EHMO calculations indicate the presence of a quasi-covalent Ti(III)-Pt(I) bond (2.721(2) A).
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