A method for homogenizing heterogeneous catalyst is described. The method is based on growing polyaminoamido (PAMAM) dendrons on silica-coated magnetic nanoparticles. After the dendronizing process, the silica-coated magnetic nanoparticles are more stable and more soluble in organic solvents. The dendronized particles are phosphonated, complexed with [Rh(COD)Cl]2, and applied in catalytic hydroformylation reactions. These new catalysts are proven to be highly selective and reactive.

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A novel method combining wet chemistry for synthesis of an Fe core, 532 nm laser irradiation of Fe nanoparticles and Au powder in liquid medium for deposition of an Au shell, and sequential magnetic extraction/ acid washing for purification has been developed to fabricate oxidation-resistant Fe@Au magnetic coreshell nanoparticles. The nanoparticles have been extensively characterized at various stages during and up to several months after completion of the synthesis by a suite of electron microscopy techniques (HRTEM, HAADF STEM, EDX), X-ray diffraction (XRD), UV-vis spectroscopy, inductively coupled plasma atomic emission spectroscopy, and magnetometry. The surface plasmon resonance of the Fe@Au nanoparticles is red shifted and much broadened as compared with that of pure colloidal nano-gold, which is explained to be predominantly a shell-thickness effect. The Au shell consists of partially fused ∼3-nm-diameter fcc Au nanoparticles (lattice interplanar distance, d ) 2.36 Å). The 18-nm-diameter magnetic core is bcc Fe single domain (d ) 2.03 Å). The nanoparticles are superparamagnetic at room temperature (300 K) with a blocking temperature, T b , of ≈170 K. After 4 months of shelf storage in normal laboratory conditions, their mass magnetization per Fe content was measured to be 210 emu/g, ∼96% of the Fe bulk value.

The members of the p-type semiconducting SrTi 1−x Fe x O 3−δ family of perovskites have been studied as novel materials for hydrocarbon sensor applications. Screen-printed thick film devices are contrasted to thin films prepared by pulsed laser deposition (PLD). In order to enhance sensor specificity towards hydrocarbons, the influence of iron content, x, film thickness and operating temperature in the range from 300 to 500• C has been investigated. In addition, the use of a catalytically active cover layer made of a platinum-doped zeolite has been successfully studied to reduce the influence of species with cross-interference. An initial model explaining the underlying sensing mechanism is proposed.

A method for supporting platinum nanoparticles on magnetite nanoparticles is described. The method requires modification of the surface of the magnetic nanoparticles with ionic liquid groups. Before modification, the magnetic nanoparticles are not stable and easily aggregate and, after modification, the magnetite nanoparticles become highly stable and soluble in polar or non‐polar organic solvents depending on the alkyl group of the linked ionic liquids. The supporting of platinum nanoparticles on the modified magnetic nanoparticles was achieved by adsorbing platinum salts (K2PtCl4) on the surface of the magnetite nanoparticles via ion exchange with the linked ionic liquid groups and then reducing them by hydrazine. The supported platinum nanoparticles were applied in the catalytic hydrogenation of alkynes in which cis‐alkenes were selectively produced, and in the hydrogenation of α,β‐unsaturated aldehydes where the allyl alcohols were obtained as the exclusive products. The new catalyst can be easily separated from the reaction mixtures by applying an external magnetic field and recycled.