Herein, uniform sized Pt–Ru bimetallic nanoparticles were deposited on a reduced graphene oxide (RGO) support using methyl ammonia borane as a reducing agent.

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We disclosed herein a series of novel 5-(2,2-difluoro-1-phenylcyclopropyl)-N-substituted-1,3,4-oxadiazol-2-amines from the reaction of 2,2-difluoro-1-phenylcyclopropane carbohydrazide and various isothiocyanates in the presence of graphene oxide (GO) and 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) under conventional and ultrasonic irradiation conditions. It was found that the reaction was completed in a short period of time with good to excellent yields by virtue of attributes offered by GO catalyst. Further, the reaction underwent smoothly in ethanol and ionic liquids. Noteworthy, GO can be recycled and reused for five cycles without considerable loss in activity. The oxidative activity and morphology of GO catalyst was confirmed by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and cyclic voltammetry (CV) techniques.[a] S.

An assembly consisting of a string of hemispherical elements arranged concentrically on a rod essentially acted as a displaced augmentative device. This assembly was placed coaxially in a three-phase fluidized bed. Nitrogen gas, an electrolyte and glass spheres were used as gas, liquid and solid phases respectively. Limiting current technique was employed to obtain mass transfer coefficient data. Maximum augmentation realized in the present study was about 18 times in comparison with homogeneous pipe flow. Present investigation revealed that the fluctuations in mass transfer coefficients in axial direction were within ±10%. The mass transfer coefficient increased with superficial gas velocity and particle diameter. The mass transfer coefficient decreased with pitch and characteristic length. Superficial liquid velocity and promoter rod diameter have not shown any noticeable influence on mass transfer coefficient. The entire mass transfer coefficient data obtained in the present study were subjected to least squares regression analysis and a correlation equation has been obtained.

This study demonstrates a convenient methodology for the decoration of Pt−Ru nanoparticles (with various morphologies like Pt‐on‐Ru and Ru‐on‐Pt) on graphene sheets. The structure, composition and morphological features of the synthesized electrocatalysts were assessed by X‐ray diffraction (XRD), High‐resolution transmission electron microscopy (HR‐TEM), Energy dispersive X‐ray spectroscopy (EDS), and cyclic voltammetry (CV). TEM analysis revealed that the Pt−Ru nanoparticles were uniformly dispersed on graphene sheets with a narrow size particle distribution. The corresponding morphology‐dependent activity of electrocatalysts towards two important anodic reactions relevant to fuel cell applications like methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) were systematically studied by CV. The results showed that Pt‐on‐Ru/RGO electrocatalysts exhibited higher catalytic activity and better stability compared to Ru‐on‐Pt/RGO, Pt/RGO and commercial Pt−Ru/C catalysts towards both MOR and EOR. Furthermore, the simple synthetic strategy demonstrated here can be extended to other bimetallic systems with improved properties for fuel cell reactions.

Herein, Pt–Pd/RGO bimetallic nanocomposites were synthesized through a halide-aided fabrication strategy. The Pt–Pd/RGO-15KI with its uniform dispersion exhibits improved methanol electro-oxidation activity compared to Pt–Pd/RGO-0KI.

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