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A stable photoactive metal-organic framework UiO-66(Zr) sensitized by adsorbed or directly added rhodamine B dye exhibited photocatalytic activity for hydrogen evolution under visible-light illumination (λ ≥ 420 nm). Using Pt as a co-catalyst, the adsorbed and directly added dye extremely enhanced the photocatalytic activity to 30 and 26 times the value afforded by bare Pt@UiO-66(Zr), respectively. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) activity as a function of thickness of the Pt shell on Pt-Ni alloy nanoparticles was established. We demonstrated that the effects of transition metals could only extend to a very thin Pt shell, which was 0.9-1.0 nm for Pt3Ni. [ABSTRACT FROM AUTHOR]

Catalysts with high activity and stability for methanol electrooxidation are crucial for the commercialization of direct methanol fuel cells. In this work, the performance of nanocrystal tungsten nitride hybrid (WN/C) supported Pt catalyst for methanol electrooxidation is reported. X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM) are adopted to investigate the physicochemical properties of WN/C and the prepared catalysts. Cyclic voltammetry, chronopotentiometry and chronoamperometry measurements are employed to study the electrocatalytic properties of the prepared catalysts. The tungsten nitride supported Pt (Pt-WN/C) catalysts exhibit significantly improved performance towards methanol electrooxidation in acidic aqueous solutions in comparison with other catalysts. The reason could predominantly originate from the synergistic effect between WN and Pt in the Pt-WN/C catalysts and the nitrogen-doping effects of the carbon supports, which could be a promising anode catalyst for direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Supported metals are traditionally prepared by impregnating a support material with the metal precursor solution, followed by reduction in hydrogen at elevated temperatures. In this study, a polymeric support has been considered. Polypyrrole (PPy) has been chemically synthesized using FeCl3 as a doping agent, and it has been impregnated with a H2PtCl6 solution to prepare a catalyst precursor. The restricted thermal stability of polypyrrole does not allow using the traditional reduction in hydrogen at elevated temperature, and chemical reduction under mild conditions using sodium borohydride implies environmental concerns. Therefore, cold RF plasma has been considered an environmentally friendly alternative. Ar plasma leads to a more effective reduction of platinum ions in the chloroplatinic complex anchored onto the polypyrrole chain after impregnation than reduction with sodium borohydride, as has been evidenced by XPS. The increase of RF power enhanced the effectiveness of the Ar plasma treatment. A homogeneous distribution of platinum nanoparticles has been observed by TEM after the reduction treatment with plasma. The Pt/polypyrrol catalyst reduced by Ar plasma at 200 watts effectively catalyzed the aqueous reduction of nitrates with H2 to yield N2, with a very low selectivity to undesired nitrites and ammonium by-products. [ABSTRACT FROM AUTHOR]

The article offers information on intermolecular hydroamination of monosubstituted allenes with secondary alkylamines catalyzed by platinum (II) and silver derivative. It mentions the effective diastereoselectivity of reactants with catalyst. It further mentions the use of nuclear magnetic resonance spectroscopy analysis for determining the stereochemistry of the purified reaction mixture.