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Here, the concept of preferential leaching of cerium oxide on ternary Pt–C–CeO2 compound is demonstrated in order to develop a cost‐effective catalyst for the cathode in proton exchange membrane fuel cells. The Pt–C–CeO2 thin film catalyst is prepared by simultaneous magnetron co‐sputtering of Pt, C, and CeO2. The morphology, structure, and composition of the Pt–C–CeO2 layer are characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, and X‐ray diffraction. Both half‐cell and single‐cell tests are performed to determine its activity and durability. During an activation electrochemical cycling procedure, CeO2 is leached from the compound, leaving behind a porous Pt–C matrix which exhibits almost 3 times higher electrochemically active surface area in comparison with pure Pt with identical loading before and even after accelerated degradation tests in the half‐cell. When used as the cathode in a single‐cell membrane electrode assembly, decomposed Pt–C–CeO2 also shows greater power density than pure Pt. [ABSTRACT FROM AUTHOR]

In this study, iron carbide nanoparticles (NPs) were prepared by the plasma‐based method using a gas aggregation source of NPs. In‐flight plasma treatment of the NPs was performed to improve their temporal stability. The auxiliary radiofrequency plasma used for the in‐flight treatment resulted in trapping of the NPs in the plasma for several 10s of seconds. Scanning electron microscopy and small‐angle X‐ray scattering analyses showed a decrease in the size of NPs due to the plasma treatment, whereas the X‐ray diffraction analysis showed that the structure of the NPs changed from amorphous iron carbide to the crystalline Fe3C (cementite). In situ and ex situ X‐ray photoelectron spectroscopy measurement confirmed better temporal stability of plasma‐treated NPs against oxidation. [ABSTRACT FROM AUTHOR]

• Sputtering conditions of thin films determine which of U-hydrides (UH 2 , α-UH 3 , β-UH 3) form. • X-ray photoelectron spectra and magnetic and transport properties obtained for all phases. • All U-hydrides are ferromagnetic. • Ferromagnetism is very robust and does not depend on structure details. Formation of thin uranium hydrides films, UH 2 and UH 3 , synthesized by direct current reactive sputtering of a uranium metal in an Ar-H 2 atmosphere, was explored using variable deposition conditions. Obtained U-H films were studied by a variety of methods, both in situ (photoelectron spectroscopy) and ex situ (x-ray diffraction, transmission electron microscopy, electrical resistivity, and magnetometry). Preparation of thin films allowed us to stabilize the non-existent in bulk UH 2 phase as well as the transient α-UH 3 (as a residual phase in UH 2) and the common stable β-UH 3 phase. All types of hydrides are ferromagnetic, the Curie temperatures of UH 2 and UH 3 (both α and β) are approx. 120 and 170 K, respectively. Ferromagnetism in the thin films is robust and does not depend on structure details while electrical resistivity data reflect disorder in both types of hydrides. [ABSTRACT FROM AUTHOR]

• Pt x Ni 100-x catalysts were deposited by magnetron co-sputtering from two targets. • Composition, morphology and thickness was adjusted by tuning deposition parameters. • Pt x Ni 100-x alloys demonstrated promising platinum utilization in PEMFCs. In this study, Pt x Ni 100-x (0 ≤ x ≤ 100) alloy catalysts were prepared using magnetron co-sputtering in order to reveal the correlation between their composition and catalytic properties as a cathode in proton exchange membrane fuel cells (PEMFCs). Fine power adjustment on magnetrons allowed to deposit alloys with precise composition and at the same time with identical thickness of 10 nm and similar morphologies. The powerful surface characterization techniques such as atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray reflectivity (XRR) and X-ray photoelectron spectroscopy (XPS) were applied to thoroughly investigate the catalytic layers. The desired composition of the films was confirmed by EDX and XRD results. All deposited layers showed similar morphologies with vertical and horizontal roughness of ~0.35 nm and ~6 nm, respectively. XRD confirmed the alloy nature of the films with one crystalline phase of the fcc PtNi. The Pt x Ni 100-x alloys showed significant enhancement of specific power (SP) comparing to the pure Pt in PEMFC. Particularly, the Pt 25 Ni 75 sample exhibited the highest SP of 24 kW/g(Pt). This catalyst showed a 2- and almost 10-fold improvement in SP with respect to the Pt film and commercial nanopowder Pt catalyst, respectively. [ABSTRACT FROM AUTHOR]