Search

Abstract: The transition of Pt from a nanoparticle to a film on SiO2 particles modified by the sputtering system with barrel-type powder sample holder (the barrel sputtering system). X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements reveal that the Pt nanoparticles grow in size with an increase in the duration of sputter deposition. The morphology of Pt changes from highly dispersed nanoparticles to a worm-like structure followed by a continuous Pt film, depending on the amount of Pt modified. Transmission electron microscopy (TEM) measurements reveal that the thin Pt film in the worm-like structure has a uniform thickness of approximately 2.6nm, indicating film growth in a two-dimensional mode followed by an island mode. [Copyright &y& Elsevier]

Abstract: Our newly developed “barrel-sputtering” technique has been employed for the surface coating of solid substrates with complex shapes such as bolts, nuts, and screws. The entire surface of the iron bolts and nuts including the flank and the root in the thread is homogeneously coated with the Au film. SEM measurements reveals that the surface of the Au film is very smooth. In the SEM measurements of the cross-sectional area, it is found that the Au film possess uniform thickness without any significant defects and/or pits. The Au film coating can also be successfully conducted on polycarbonate bolts and small SUS screws. The results provide evidences that the sputter deposition takes place in “three-dimensionally.” [Copyright &y& Elsevier]

Abstract: Micron-sized spherical polymer particles were homogeneously coated with Au, Ag, Pd, Cu, and Ni by the barrel sputtering technique. Surface coating was successfully performed independent of the sputtered metal and the diameter of the polymer particles used. Optical microscope observations revealed a mirror-like appearance with a color that depended on the coated metal. SEM and EDX studies revealed that the surface of metal-coated samples was very smooth and the sputtered metal was homogeneously distributed over the entire sample surface. The amount of coated metal was evaluated using TG–DTA and ICP-AES measurements. The thickness of the metal film was within several 10nm. [Copyright &y& Elsevier]

Abstract A physical sputtering method was adopted to prepare graphene supported highly dispersed and uniform sized Ru NPs without using any solutions, surfactants and reductants. The Ru/G-spu exhibited excellent catalytic performance for HER and hydrolytic dehydrogenation of NaBH 4. Especially for HER in alkaline media, it performed superior electrocatalytic activity over Pt/C. The superior catalytic performance can be attributed to the high exposed surface area and dispersion of Ru NPs on graphene with the open 2D layer structure, which demonstrates the physical sputtering method is a facile and efficient technique to prepare graphene supported metal NPs with excellent structure and catalytic properties. Highlights • Graphene supported highly dispersed Ru NPs was prepared by physical sputtering. • The physical sputtering avoided using any solvent, surfactant and reducing agent. • The Ru/G-spu catalyst exhibited excellent catalytic performance for HER. [ABSTRACT FROM AUTHOR]

Abstract: The present study investigated physical and electrochemical properties of carbon-supported Pt–Ru alloy (Pt–Ru/C) samples prepared on various carbon supports by using a sputtering system with barrel-type powder sample holder (the barrel sputtering system). For this system, the deposited Pt–Ru nano-particles had uniform sizes of less than 4nm and homogeneous atomic ratios of Pt and Ru of ca. 50:50at.% independent of a specific surface area of the carbon support. Further, the electrochemical properties of the prepared samples obtained from CO stripping voltammetry were almost identical. These were completely different from the result for wet process showing that the physical and electrochemical properties of samples prepared by an impregnation method changed with the specific surface area of the carbon support. [Copyright &y& Elsevier]

Highlights: [•] New Cu/ZnO/H-ZSM5 catalyst is prepared by physical sputtering. [•] Direct DME synthesis from syngas is accomplished efficiently by this new catalyst. [•] Wet impregnation method makes Cu ion difficult to reduce due to zeolite. [Copyright &y& Elsevier]

Abstract: The mm-sized capsule catalyst Co/SiO2-Z with the H-type zeolite (HZSM-5) as the shell, and the Co/SiO2-Z-Sp-Pd capsule catalyst with Pd loaded by sputtering method, as well as the Co/SiO2-Z-IW-Pd capsule catalyst, loading the Pd by incipient wetness impregnation, were prepared and used for isoparaffin direct synthesis by Fischer–Tropsch synthesis reaction from syngas with H2/CO ratio of 2/1 at 1.0MPa and 533K. The analysis results of XRD, SEM, EDS and NH3-TPD showed that a compact HZSM-5 shell was formed on the Co/SiO2 pellet, and the metallic Pd was well sputtered on the surface of the HZSM-5 shell for the Co/SiO2-Z-Sp-Pd catalyst. The isoparaffin and olefin selectivity increased in the FTS reactions on the HZSM-5 capsule catalyst than on the Co/SiO2 catalyst. The selectivity of isoparaffins increased, and the selectivity of olefins decreased when using the Co/SiO2-Z-Sp-Pd catalyst, compared with the Co/SiO2-Z catalyst or the Co/SiO2-Z-IW-Pd catalyst, because metallic Pd introduced by sputtering on the zeolite shell could hydrogenate olefins efficiently. It was suitable to use the sputtering method for the preparation of the zeolite capsule catalyst loaded with metallic Pd, as conventional impregnation method could not reduce Pd cation due to the strong interaction from zeolite surface. The CO conversion, CH4 and CO2 selectivity on the catalyst of Co/SiO2-Z-Sp-Pd increased with temperature increasing from 513K to 553K. At elevated temperature, the isoparaffin selectivity also increased while the olefin selectivity was suppressed. [Copyright &y& Elsevier]

Abstract: The CO oxidation on non-alloyed Pt and Ru electrocatalysts prepared by the polygonal barrel-sputtering method was investigated. Samples were prepared by sputtering Pt and Ru separately at room temperature. From the X-ray diffraction (XRD) measurement of the sample prepared on a SiO2 glass plate, it was found that the sputtered metals are non-alloyed. Subsequently, the non-alloyed Pt and Ru electrocatalysts were prepared by the polygonal barrel-sputtering method using carbon powder as a support. The XRD patterns of these samples showed a single and very broad peak supporting the hypothesis of the non-alloyed Pt and Ru. No separate Ru reflections were visible, which could be attributed to Ru particle sizes smaller than 4nm, as obtained by transmission electron microscopy (TEM). CO oxidation on the non-alloyed Pt and Ru electrocatalysts were evaluated by CO stripping voltammetry. This measurement revealed that the lower peak potential of CO oxidation varies, depending on the Pt content and the sputtering order. In addition, it was assumed that the CO oxidation reaction site for non-alloyed Pt and Ru electrocatalyst has a limited area including direct contact sites between the Pt and Ru particles. [Copyright &y& Elsevier]