Resultados de investigación

12 pages. -- Figure S1-S18. -- Table S1. Atomic percentages determined by XPS in the electrodes after OER. -- Table S2. Comparison of the CoFeP-based electrodes for OER in 1 M KOH in chronological order., The development of high current density anodes for the oxygen evolution reaction (OER) is fundamental to manufacturing practical and reliable electrochemical cells. In this work, we have developed a bimetallic electrocatalyst based on cobalt–iron oxyhydroxide that shows outstanding performance for water oxidation. Such a catalyst is obtained from cobalt–iron phosphide nanorods that serve as sacrificial structures for the formation of a bimetallic oxyhydroxide through phosphorous loss concomitantly to oxygen/hydroxide incorporation. CoFeP nanorods are synthesized using a scalable method using triphenyl phosphite as a phosphorous precursor. They are deposited without the use of binders on nickel foam to enable fast electron transport, a highly effective surface area, and a high density of active sites. The morphological and chemical transformation of the CoFeP nanoparticles is analyzed and compared with the monometallic cobalt phosphide in alkaline media and under anodic potentials. The resulting bimetallic electrode presents a Tafel slope as low as 42 mV dec–1 and low overpotentials for OER. For the first time, an anion exchange membrane electrolysis device with an integrated CoFeP-based anode was tested at a high current density of 1 A cm–2, demonstrating excellent stability and Faradaic efficiency near 100%. This work opens up a way for using metal phosphide-based anodes for practical fuel electrosynthesis devices., Peer reviewed

11 pages. -- Experimental Section. Chemicals. -- Synthesis of Hexaaminobenzene (HAB). -- Synthesis of C2N. --Synthesis of PdH0.58@C2N, Pd@C2N, PdH0.58 and PdH0.58/C2N. -- -- Structural characterization. -- Electrochemical Measurements. -- Computational method. -- Figures S1-S8. -- Table S1. Summary of the FOR activity and stability of Pd-based nanoalloys., The lack of electrocatalysts for the formate oxidation reaction (FOR) hampers the deployment of direct formate fuel cells (DFFCs). To overcome this limitation, herein, we detail the production of palladium hydride particles supported on C2N (PdH0.58@C2N) via a facile method. PdH0.58@C2N displays excellent FOR performance, reaching current densities up to 5.6 A·mgPd–1 and stable cycling and chronoamperometric operation. The Pd lattice expands due to the hydrogen intercalation. Besides, an electronic redistribution associated with the distinct electronegativity of Pd and H is observed. Both phenomena modify the electron energy levels, enhancing the activity and stability of the composite catalyst. More specifically, differential functional theory calculations show H intercalation to downshift the Pd d-band center in Pd0.58@C2N, weakening adsorbate binding and accelerating the FOR rate-determining step., Peer reviewed

Chemicals, material characterizations, structural characterization, electrochemical measurements, MEA fabrication and direct ethanol fuel cell performance test, theoretical modeling and calculations; additional TEM, AC-HRTEM, HRTEM, HAADF-STEM images, corresponding FFT spectrum and GPA analysis; XRD pattern; Tafel slope curve; schematic illustration of mechanism for EOR; CO-TPD and CO–DRIFTS spectra; 1H NMR spectra; work functions and electron density differences diagram; and calculation details of Faradaic efficiency, mass activity, price activity, Engineering lattice strain, electronic structure, and crystallinity in palladium alloys offers a promising approach to significantly enhance their electrocatalytic performance. In this work, we present a versatile strategy to synthesize Pd-based phosphide alloys integrated with non-noble metal atoms (Pd-M-P; M = Co, Ni, Cu), characterized by expanded lattice structures and a crystalline–amorphous core–shell architecture. Catalytic performance assessments revealed that CuPdP exhibits an impressive mass activity of 7.96 A mgPd–1 for the ethanol oxidation reaction (EOR), which is 10.6 times higher than that of commercial Pd/C. This performance enhancement can be attributed to the precisely engineered lattice tensile strain and the strong p–d hybridization interaction between P and Pd. Density functional theory calculations further confirmed that these factors facilitate enhanced OH adsorption and weakened CO adsorption, thereby significantly improving EOR performance. This study presents an effective strategy for the atomic-level engineering of palladium alloy nanomaterials to achieve good electrocatalytic performance, providing a method for designing highly active catalysts., Peer reviewed

11 pages. -- Experimental and theoretical methods. -- Results., Peer reviewed

SEM images and EDS spectra of MnxOy@Ni(OH)2 electrodes; DFT-calculated adsorption energies on NiOOH, Mn3O4, and NiOOH/Mn3O4–MnO2 surfaces; CV curves and scan rate-dependent behavior; analysis of diffusion and kinetic parameters; post-CV XPS spectra of Mn and Ni; chronoamperometric stability tests and LSV curves before/after operation; optimized structures of OER intermediates (*OH, *O, *OOH) under AEM and LOM pathways; ICP-OES analysis of Mn/Ni ratios; thermodynamic, kinetic, and electrochemical parameters for OER; XPS quantification of surface states pre- and postcycling; benchmarking of overpotential performance versus literature, We report a colloidal synthesis strategy for producing MnxOy@Ni­(OH)2 nanoheterostructures under mild conditions, i.e., low temperature and ambient pressure. The role of carboxylic acid ligands in directing the synthesis is systematically explored, revealing that lower ligand concentrations along with low-molecular weight molecules favor the formation of well-defined MnxOy@Ni­(OH)2 heterostructures. Electrochemical characterization demonstrates that the resulting nanocomposites exhibit significantly enhanced electrochemical surface area and oxygen evolution reaction (OER) activity compared to their single-component counterparts. Specifically, MnxOy@Ni­(OH)2 achieves a low overpotential of 299 mV at 10 mA cm–2, a Tafel slope of 61 mV dec–1, and a low charge transfer resistance of 9 Ω. The improved OER performance is attributed to the synergistic effect between the Ni­(OH)2 nanosheets, which facilitate *OOH intermediate formation, and the MnO2 component, known for its intrinsic catalytic activity. Additionally, Mn3O4 serves as a stabilizing phase and precursor to MnO2, contributing to the overall durability and structural integrity of the catalyst., Peer reviewed

Eukaryotic chromosome segregation relies on the assembly of a bipolar machinery based on microtubules (MTs), named the mitotic spindle. Formation of the mitotic spindle follows a force balance mechanism that ensures the proper capture and separation of sister chromatids. Many proteins have been involved in the establishment of this force balance, although kinesin 5 is well recognized as the major outward pushing force generator, since its inactivation results in monopolar, non-functional spindles. In order to find additional players in the force balance mechanism, we have performed a suppressor screen using a conditional allele of the fission yeast kinesin 5 ortholog Cut7. This screen identified that the lack of the PP6 phosphatase partially suppresses cut7 phenotypes, at least by defective translation of MT regulators, such as the minus end-directed kinesin Klp2, the MT stabilizer Alp7 and the MT bundler Ase1, impacting on the force balance mechanism. Additionally, our data show that the Elongator complex, a target activated by PP6 for efficient tRNA modification, also contributes to the force balance, albeit to a lesser extent. Importantly, this complex has recently been implicated in direct MT polymerization in metazoans, a role not shared by its fission yeast counterpart., Peer reviewed

Eukaryotic chromosome segregation relies on the assembly of a bipolar machinery based on microtubules (MTs), named the mitotic spindle. Formation of the mitotic spindle follows a force balance mechanism that ensures the proper capture and separation of sister chromatids. Many proteins have been involved in the establishment of this force balance, although kinesin 5 is well recognized as the major outward pushing force generator, since its inactivation results in monopolar, non-functional spindles. In order to find additional players in the force balance mechanism, we have performed a suppressor screen using a conditional allele of the fission yeast kinesin 5 ortholog Cut7. This screen identified that the lack of the PP6 phosphatase partially suppresses cut7 phenotypes, at least by defective translation of MT regulators, such as the minus end-directed kinesin Klp2, the MT stabilizer Alp7 and the MT bundler Ase1, impacting on the force balance mechanism. Additionally, our data show that the Elongator complex, a target activated by PP6 for efficient tRNA modification, also contributes to the force balance, albeit to a lesser extent. Importantly, this complex has recently been implicated in direct MT polymerization in metazoans, a role not shared by its fission yeast counterpart., Peer reviewed

A: Serial dilution assay of the wild type, ekc1∆, cut7–24 and cut7–24 ekc1∆ strains incubated for 3 days at the indicated temperatures. B: SDS PAGE analysis of Cut7-3xHA levels on wild type or ppe1∆ cells. The upper panel corresponds to the blot incubated with an anti-HA antibody, while the bottom panel corresponds to the blot incubated with an anti-tubulin antibody. C: Plot showing the total Cut7-3xHA levels relative to the corresponding tubulin levels in wild type and ppe1∆ cells. n for wild type: 3; n for ppe1∆: 3. a.u.: arbitrary units. Statistical significance was determined using a T-test (p = 0.086). D: Upper panel, PhosTag SDS PAGE analysis of Cut7-3xHA in asynchronous and mitotically blocked nda3-KM311 cells in the presence or absence of Ppe1. Bottom panel, the same samples submitted to SDS PAGE analysis using an anti-tubulin antibody. E: SDS PAGE analysis of Pkl1-13xMyc levels on wild type or ppe1∆ cells. The upper panel corresponds to the blot incubated with an anti-Myc antibody, while the bottom panel corresponds to the blot incubated with an anti-tubulin antibody. F: Plot showing the total Pkl1-13xMyc levels relative to the corresponding tubulin levels in wild type and ppe1∆ cells. n for wild type: 3; n for ppe1∆: 3. a.u.: arbitrary units. Statistical significance was determined using a T-test (p = 0.121). G: Upper panel, PhosTag SDS PAGE analysis of Pkl1-13xMyc in asynchronous and mitotically blocked nda3-KM311 cells in the presence or absence of Ppe1. Bottom panel, the same samples submitted to SDS PAGE analysis using an anti-tubulin antibody., Peer reviewed

A: Serial dilution assay of the wild type, elp3∆, cut7–24, cut7–24 elp3∆, cut7–22 and cut7–22 elp3∆ strains incubated for 3 days at the indicated temperatures. B: Selected kymographs showing interphasic MT dynamics in wild type, ppe1∆, elp3∆ and elp3-YY527AA cells expressing GFP-Atb2, showing the inverted green channel in a grey scale. Scale bar: 5 μm. C: Plot showing MT growth rate of the indicated strains expressing GFP-Atb2 (n for wild type: 74; n for ppe1∆: 87; n for elp3∆: 79; n for elp3-YY527AA: 79). Statistical differences were determined using a T-test (wt vs. ppe1∆, p = 0.409; wt vs. elp3∆, p = 0.374; wt vs. elp3-YY527AA, p = 0.001). D: Plot showing MT catastrophe rate of the indicated strains expressing GFP-Atb2 (n for wild type: 95; n for ppe1∆: 73; n for elp3∆: 82; n for elp3-YY527AA: 88). Statistical differences were determined using a T-test (wt vs. ppe1∆, p = 0.054; wt vs. elp3∆, p = 0.003; wt vs. elp3-YY527AA, p = 0.294). E: Plot showing MT dwelling time at the cell end of the indicated strains expressing GFP-Atb2 (n for wild type: 63; n for ppe1∆: 67; n for elp3∆: 67; n for elp3-YY527AA: 65). Statistical differences were determined using a T-test (wt vs. ppe1∆, p = 0.931; wt vs. elp3∆, p = 0.500; wt vs. elp3-YY527AA, p = 0.667). F: Maximum intensity projections from confocal time lapse images of wild type cells expressing mCherry-Atb2 and Elp3 or Elp4 fused to GFP. The upper series shows the magenta (mCherry-Atb2) and green (Elp3-GFP or Elp4-GFP) merged channels. The bottom series shows the inverted green channel in a grey scale. Time 0 corresponds to mitotic entry. The dashed line represents the cell contour. Scale bar: 2 μm. G: Western-blot analysis of SDS PAGE of Elp3-GFP and Elp4-GFP from the strains shown in C., Peer reviewed

A: Serial dilution assay of the wild type, ppe1∆, klp2∆, ppe1∆ klp2∆, cut7–22, cut7–22 ppe1∆, cut7–22 klp2∆ and cut7–22 ppe1∆ klp2∆ strains incubated for 3 days at the indicated temperatures. B: Serial dilution assay of the wild type, ppe1∆, alp7∆, ppe1∆ alp7∆, cut7–22, cut7–22 ppe1∆, cut7–22 alp7∆ and cut7–22 ppe1∆ alp7∆ strains incubated for 3 days at the indicated temperatures. C: Serial dilution assay of the wild type, ppe1∆, ase1∆, ppe1∆ ase1∆, cut7–22, cut7–22 ppe1∆, cut7–22 ase1∆ and cut7–22 ppe1∆ ase1∆ strains incubated for 3 days at the indicated temperatures., Peer reviewed