Colloidal platinum nanoparticles with diameters of 2-5 nm on carbon supports are currently regarded as the best catalysts for the oxygen reduction reaction. However, the particle size is limited by the conventional preparation methods that are used to synthesize small platinum particles; the inherent activity of ultrasmall nanoparticles has not yet been revealed. We present a practical synthesis for ultrafine subnanometre platinum clusters using a spherical macromolecular template with no disorder in molecular weight or structure. The template, a phenylazomethine dendrimer, offers control of the number of metal complexes in an assembly through stepwise complexation, allowing the complexes to accumulate in discrete nano-cages. Subsequent reduction of Pt(IV) chloride to Pt(0) results in the formation of platinum clusters composed of a defined number of atoms. As a result of exceptionally small particle size, the clusters exhibit very high catalytic activity for the four-electron reduction of oxygen molecules.
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http://dx.doi.org/10.1038/nchem.288 | DOI Listing |
J Colloid Interface Sci
January 2025
Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing 100084, PR China. Electronic address:
Exploring suitable dual active site and metal-substrate interface effect is essential for designing efficient and robust electrocatalysts across a wide pH range for the hydrogen evolution reaction (HER). Herein, alloyed platinum-ruthenium clusters supported on nanosheet-assembled molybdenum carbide microflowers (PtRu/MoC) are reported as efficient pH-universal electrocatalysts for HER. Due to dual active site and metal-substrate interface effect, the optimized PtRu/MoC electrocatalyst exhibits extremely low overpotentials (η) of 9, 19, and 33 mV to deliver 10 mA cm in 0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Tianjin University, School of Materials science and engineering, School of Materials Science and Engineering, Tianjin University, 300072, Tianjin, CHINA.
Fe-N-C catalyst is the most promising alternative to platinum catalyst for proton-exchange membrane fuel cells (PEMFCs), however its high performance cannot be maintained for a long enough time in device. The construction of a new Fe coordination environment that is different from the square-planar Fe-N 4 configuration in Fe-N-C catalyst is expected to break current stability limits, which however remains unexplored. Here, we report the conversion of Fe-N-C to a new FeNxSey catalyst, where the Fe sites are three-dimensionally (3D) co-coordinated by N and Se atoms.
View Article and Find Full Text PDFJ Control Release
January 2025
State Key Laboratory of Natural Medicines, China Pharmaceutical University, 639 Longmian Avenue, Nanjing 211198, China; NMPA Key Laboratory for Research and Evaluation of Pharmaceutical Preparations and Excipients, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, China; Department of Pharmaceutics, School of Pharmacy, 639 Longmian Avenue, Nanjing 211198, China. Electronic address:
Active-targeting nanomedicines have been widely employed in cancer treatment for increasing therapeutic index. However, the limited permeability caused by the binding site barrier (BSB) and size hindrances compromises their clinical antitumor efficacy in patients. Herein, learning from the liquid-liquid phase separation (LLPS) of bio-macromolecules, we report phase-separating glycopeptides (HEP) from polyhistidine (PHis) grafted hyaluronic acid (HA), which can sense the tumor extracellular pH and concomitantly overcome size and BSB dilemmas for enhanced tumor penetration.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Hydrogen spillover is an important process in catalytic hydrogenation reactions, facilitating H activation and modulating surface chemistry of reducible oxide catalysts. This study focuses on the unveiling of platinum-induced hydrogen spillover on monoclinic tungsten trioxide (γ-WO), employing ambient pressure X-ray photoelectron spectroscopy, density functional theory calculations and microkinetic modeling to investigate the dynamic evolution of surface states at varied temperatures. At room temperature, hydrogen spillover results in the formation of W and hydrogen intermediates (hydroxyl species and adsorbed water), facilitated by Pt metal clusters.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Engineering Research Center of Advanced Functional Material Manufacturing of Ministry of Education, School of Chemical Engineering, Zhengzhou University, Zhengzhou, 450001 Henan, China; National Key Laboratory of Coking Coal Green Process Research, Zhengzhou University, Zhengzhou 450001, Henan, China. Electronic address:
Hydrogen production via electrocatalytic water splitting has garnered significant attention, due to the growing demand for clean and renewable energy. However, achieving low overpotential and long-term stability of water splitting catalysts at high current densities remains a major challenge. Herein, a CoP@CoNi layered double hydroxide (LDH) electrode was synthesized via a two-step electrodeposition process, demonstrating oxygen evolution reaction, with an overpotential (ƞ) of 373 mV and a Tafel slope of 64.
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